A farsighted person has a nearpoint of 60 cm from her eyes. She wants glasses that will let her see objects at a distance of only 25 cm from her eyes. Determine the focal length of the glasses needed if the glasses are 2 cm and 3 cm from her eyes. (Remember, a converging lens has a positive focal length and a diverging lens has a negative focal length.)
f2 cm = ? cm
2) f3 cm = ? cm

Answers

Answer 1

The glasses needed are again diverging lenses, with a focal length of 666.7 cm. The near point of a person is the closest distance from the eye at which an object can be seen clearly. For this farsighted person, the near point is 60 cm, which means that she has difficulty seeing objects that are closer than that.

To correct her vision, the person needs glasses that will create an image of nearby objects at a distance of 25 cm from her eyes. We can use the thin lens formula to find the focal length of the glasses needed:

1/f = 1/d_o + 1/d_i

where f is the focal length of the lens, d_o is the object distance (distance of the object from the lens), and d_i is the image distance (distance of the image from the lens). For a converging lens, the focal length is positive, and for a diverging lens, it is negative.

If the glasses are 2 cm from her eyes, the object distance is:

d_o = 60 cm - 2 cm = 58 cm

The image distance is:

d_i = -25 cm

since the image is formed on the same side as the object, and the image distance is negative for a virtual image. Therefore, we can solve for the focal length:

1/f = 1/d_o + 1/d_i

1/f = 1/58 cm - 1/25 cm

1/f = -0.0012 [tex]cm^{(-1)}[/tex]

f = -833.3 cm

Since the focal length is negative, the glasses needed are diverging lenses, with a focal length of 833.3 cm.

If the glasses are 3 cm from her eyes, the object distance is:

d_o = 60 cm - 3 cm = 57 cm

The image distance is still:

d_i = -25 cm

We can again solve for the focal length:

1/f = 1/d_o + 1/d_i

1/f = 1/57 cm - 1/25 cm

1/f = -0.0015 [tex]cm^{(-1)}[/tex]

f = -666.7 cm

Therefore, the glasses needed are again diverging lenses, with a focal length of 666.7 cm.

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Related Questions

Light having a speed in vacuum of 3. 0 × 108 m/s enters a liquid of refractive index 2. 0. In this liquid, its speed will be.

Answers

When light enters a medium with a different refractive index, its speed changes. The relationship between the speed of light in a vacuum and its speed in a medium is given by the equation:

n = c/v

where n is the refractive index of the medium, c is the speed of light in a vacuum, and v is the speed of light in the medium.

Rearranging this equation, we get:

v = c/n

Substituting the values given in the question, we get:

v = (3.0 × 10^8 m/s)/2.0

v = 1.5 × 10^8 m/s

Therefore, when light enters a liquid with a refractive index of 2.0, its speed will be 1.5 × 10^8 m/s.

To find the speed of light in a liquid with a refractive index of 2.0, given that the speed of light in a vacuum is 3.0 × 10^8 m/s, you can use the following formula:

Speed of light in liquid = (Speed of light in vacuum) / Refractive index

Step-by-step explanation:

1. Write down the given values: Speed of light in vacuum = 3.0 × 10^8 m/s and Refractive index = 2.0.
2. Apply the formula: Speed of light in liquid = (3.0 × 10^8 m/s) / 2.0
3. Calculate: Speed of light in liquid = 1.5 × 10^8 m/s

So, in this liquid with a refractive index of 2.0, the speed of light will be 1.5 × 10^8 m/s.

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Two charged objects have a repulsive force of 0.080 N. If the distance separating the objects is halved, then what is the new force?

Answers

The force between two charged objects is inversely proportional to the square of the distance separating them. This means that if the distance is halved, the force will increase four times. Therefore, the new force will be 0.320 N.

What is force?

Force is an influence that causes a change in the motion, direction, or shape of an object. It is the result of an interaction between two objects, and can be attractive or repulsive. Forces can be categorized as contact forces, such as a push or pull, or non-contact forces, such as gravity. Force is measured in Newtons (N), and is the product of mass multiplied by acceleration. Forces cause acceleration, and the magnitude of acceleration is directly proportional to the magnitude of the force. Forces can act in different directions, and the sum of all forces acting on an object is known as the net force. The law of inertia states that an object in motion will stay in motion until a force acts to change its direction or speed. Force is a crucial concept in physics, and is an important part of understanding how the world works.

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use the equation v is congruent to 331 m/s + (0.61 m/s) (t/1degree C) to calculate the speed of the sound in air at 30 degrees C

Answers

The speed of sound in air at 30°C will be approximately 349.3 m/s.

we can use the given equation to calculate the speed of sound in air at 30°C.

The equation is:

v = 331 m/s + (0.61 m/s) (t/1°C)

where:

v = speed of sound

t = temperature in °C

We need to calculate the speed of sound at 30°C, so we can substitute t = 30°C in the above equation:

v = 331 m/s + (0.61 m/s) (30°C/1°C)

v = 331 m/s + (0.61 m/s) (30)

v = 331 m/s + 18.3 m/s

v = 349.3 m/s

Therefore, the speed of sound in air at 30°C is approximately 349.3 m/s.

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A 3. 0 kg solid sphere (radius = 0. 15 m ) is released from rest at the top of a ramp and allowed to roll without slipping. The ramp is 0. 65 m high and 5. 7 m long. Part A Part complete When the sphere reaches the bottom of the ramp, what is its total kinetic energy? Express your answer using two significant figures. K = 19 J Previous Answers Correct Part B When the sphere reaches the bottom of the ramp, what is its rotational kinetic energy? Express your answer using two significant figures.

When the sphere reaches the bottom of the ramp, what is its translational kinetic energy?

Express your answer using two significant figures

Answers

The total kinetic energy of the sphere when it is moving is equal to the potential energy when it is at rest at a height of 0.65 m. Then, the kinetic energy of the sphere is 19.11 J.

The kinetic energy of an object is the energy generated by virtue of its motion. The energy which is stored in an object when it is at rest is called its potential energy. When the object starts to move, its potential energy starts to convert to kinetic energy.

Here, when the sphere, starts rolls down, its potential energy becomes kinetic energy.

thus, 1/2 mv² = mgh

given that mass of the sphere m = 3 kg

height of the ramp h = 0.65 m

g = 9.8 m/s²

Then, k = mgh before it reaches the ground.

mgh = 3kg × 0.65 m × 9.8 m/s²

        = 19.11 J.

Therefore, the kinetic energy of the sphere at the bottom of the ramp will be 19.11 J.

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Two ladybugs sit on a rotating disk, as shown in the figure (the ladybugs are at rest with respect to the surface of the disk and do not slip). Ladybug 1 is halfway between ladybug 2 and the axis of rotation.
What is the angular speed of ladybug 1?
A. 1/2 of lady bug 2
B. the same as ladybug 2
C. 2x the speed of lady bug 2
D. 1/4 lady bug 2

Answers

When ladybugs sit on a rotating disk, their positions and motions depend on their distance from the axis of rotation. In this case, ladybug 1 is located halfway between ladybug 2 and the axis of rotation.

Therefore, ladybug 1 is closer to the axis than ladybug 2, which means it has a smaller distance to travel in the same amount of time as the disk rotates. Ladybug 1 is therefore moving at a slower speed than ladybug 2, but still in the same direction as the rotation.

As for the options given, ladybug 1's speed is not the same as ladybug 2's, so option B is incorrect. Option D, which suggests ladybug 1 is moving at 1/4 of ladybug 2's speed, is also incorrect as their speeds are not directly proportional to their distances from the axis of rotation. It is important to note that both ladybugs are at rest with respect to the surface of the disk and do not slip, which means they move along with the disk without sliding or falling off.

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You are talking to your grandmother—who grew up in the 1960s—about climate change. She asks you a lot of questions about the issue, and in the end, isn’t sure she believes it to be a problem. Upon reflection, what belief about climate that was popular in the 1960s might have influenced your grandmother’s conclusion that she isn’t sure climate change is a problem?

A. Climate only consisted of temperature, rather than the modern belief that climate includes other aspects.
B. The Earth had four climate stages, and we are not due for a fifth for 10,000 years.
C. Climate change happened over hundreds and thousands of years, not quickly.
D. The little ice age was still happening, so our temperatures should be going down.
*Answer is not A*

Answers

The belief about climate that was popular in the 1960s might have influenced your grandmother’s conclusion that she isn’t sure climate change is a problem (C). Climate change happened over hundreds and thousands of years, not quickly is correct option.

Your grandmother's conclusion that she doesn't think climate change is a problem may have been affected by the 1960s climate belief C. It was thought that climate change occurred slowly, spanning thousands of years. The rate at which the climate could change at the time was not well understood by the scientific community, and it was widely believed that climate change was a slow and gradual process. People may find it difficult to embrace the idea that human actions could create sudden and severe changes in the Earth's climate system because they perceive climate change as a gradual process.

Therefore, the correct option is (c).

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Suppose the rate of change of the magnetic field applied to a loop of wire is tripled, what happens to the induced emf in the loop assuming all of the other parameters remain unchanged?.

Answers

According to Faraday's Law of Induction, the induced emf in a loop of wire is directly proportional to the rate of change of the magnetic field applied to the loop. Therefore, if the rate of change of the magnetic field applied to the loop is tripled, the induced emf in the loop will also triple assuming all other parameters remain unchanged.

This is because a higher rate of change of the magnetic field induces a stronger emf in the loop.

Suppose the rate of change of the magnetic field applied to a loop of wire is tripled, what happens to the induced emf in the loop assuming all of the other parameters remain unchanged?

According to Faraday's Law of Electromagnetic Induction, the induced electromotive force (emf) in a loop of wire is directly proportional to the rate of change of the magnetic field (ΔB/Δt) through the loop. Mathematically, this can be expressed as:

Induced emf = -N * (ΔB/Δt)

where N is the number of turns in the loop.

Since the rate of change of the magnetic field (ΔB/Δt) is tripled, we can modify the equation:

Induced emf_new = -N * (3 * ΔB/Δt)

Notice that the new induced emf is three times the original induced emf:

Induced emf_new = 3 * Induced emf_original

So, if the rate of change of the magnetic field applied to a loop of wire is tripled, the induced emf in the loop will also be tripled, assuming all other parameters remain unchanged.

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how to determine the amount of heat, q, entering or leaving the substance

Answers

q = mcΔT can determine the amount of heat, q, entering or leaving the substance

What exactly does "specific heat" mean?

The amount of heat needed to raise a substance's temperature by one degree Celsius per gram is known as its specific heat. Typically, calories or joules per gram per degree Celsius are used as the units of specific heat.

The movement of minuscule atoms, molecules, or ions in solids, liquids, and gases produces heat energy. From one thing to another, heat energy can be exchanged. Heat is the flow or transfer that occurs as a result of the temperature differential between two objects.

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Which statements describe the characteristics of a magnet? select four options.

Answers

Magnets have two poles, attract specific materials, can repel and attract each other, and generate a magnetic field. These four characteristics describe the primary features of a magnet.


The characteristics of a magnet are:
1. A magnet has two poles, north and south.
2. A magnet can attract iron, cobalt, and nickel.
3. A magnet can repel another magnet if their poles are the same.
4. A magnet can create a magnetic field around it.
Hi! To answer your question about the characteristics of a magnet, I have selected four key features:

1. Magnets have two poles: One of the primary characteristics of a magnet is that it has two poles - a north pole and a south pole. These poles are responsible for the magnetic field generated by the magnet.

2. Magnets attract certain materials: Magnets are known to attract materials such as iron, nickel, and cobalt. These materials, when in contact with a magnet, experience a force that pulls them towards the magnet.

3. Magnets can repel and attract each other: When two magnets are brought close to each other, they can either attract or repel one another. If the opposite poles (north and south) are facing each other, they will attract, while if the same poles (north-north or south-south) are facing each other, they will repel.

4. Magnets generate a magnetic field: A magnet generates a magnetic field around itself, which is responsible for the attraction or repulsion of other magnets and magnetic materials. This field is invisible and can be represented by magnetic field lines.

In summary, magnets have two poles, attract specific materials, can repel and attract each other, and generate a magnetic field. These four characteristics describe the primary features of a magnet.

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a 3.4-a current is flowing in a 22-h inductor. a switch opens, interrupting the current in 1.0 ms . part a find the induced emf in the inductor.

Answers

According to the question the induced emf in the inductor is 76,400 V

What is inductor?

An inductor is an electrical component that stores energy in the form of a magnetic field. It is made up of a coil of wire usually with a ferromagnetic core, although the core can sometimes be air. When current passes through the coil, it creates a magnetic field, which stores energy in the form of a magnetic field. Inductors are used in many electronic circuits, such as filters, oscillators, transformers and voltage regulators. They can also be used to create and store a voltage in a capacitive circuit.

The induced emf in an inductor is given by the equation:
e = L*(di/dt)
where L is the inductance and di/dt is the rate of change of current.
In this case, the rate of change of current is calculated by taking the initial current, subtracting the final current (which is zero after the switch is opened) and dividing by the time interval (1.0 ms).
Therefore, the induced emf in the inductor is:
e = 22 H * (3.4 A / 0.001 s) = 76,400 V.

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A coil of wire with a resistance of 0.45 Ω has a self-inductance of 0.083 H. If a 6.0-V battery is connected across the ends of the coil and the current in the circuit reaches an equilibrium value, what is the stored energy in the inductor?
A) 7.4 J
B) 4.6 J
C) 1.6 J
D) 5.1 J
E) 3.4 J

Answers

A coil of wire with a resistance of 0.45 Ω has a self-inductance of 0.083 H. If a 6.0-V battery is connected across the ends of the coil and the current in the circuit reaches an equilibrium value, the stored energy in the inductor is 7.4J.

The energy stored in an inductor is given by the formula:
$U = \frac{1}{2} L I^2$ w
here U is the stored energy, L is the self-inductance, and I is the current in the circuit.
First, we need to find the current in the circuit. We can use Ohm's law:
$V = IR$
where V is the voltage of the battery, and R is the resistance of the coil. Solving for I, we get:
$I = \frac{V}{R} = \frac{6.0\text{ V}}{0.45\ \Omega} = 13.3\text{ A}$
Now we can use the formula for stored energy:
$U = \frac{1}{2} L I^2 = \frac{1}{2} (0.083\text{ H})(13.3\text{ A})^2 = \boxed{7.4\text{ J}}$
Therefore, the stored energy in the inductor is 7.4 J.This is an example of an endothermic process, as the temperature of the coil increases as energy is stored in the inductor.

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Since 1990, the hubble space telescope has been orbiting earth and sending back images of space for astronomers to view and interpret. What benefit is there to a telescope that orbits earth?.

Answers

The primary benefit of a telescope that orbits Earth, like the Hubble Space Telescope, is that it avoids the interference caused by Earth's atmosphere, providing clearer and more detailed images of space.


1. Atmospheric distortion: Earth's atmosphere distorts light from celestial objects, which reduces the clarity of images captured by ground-based telescopes. An orbiting telescope avoids this issue, resulting in sharper images.

2. Light pollution: Orbiting telescopes are not affected by the artificial light generated by human activities, which can hinder the observation of faint celestial objects.

3. Continuous observation: A telescope in space can observe the sky continuously without the need for daytime breaks or being affected by weather conditions, thus increasing the amount of data collected.

In conclusion, a telescope that orbits Earth, such as the Hubble Space Telescope, offers significant advantages over ground-based telescopes, including improved image clarity, reduced light pollution, and uninterrupted observation time. These benefits enable astronomers to gain a better understanding of the universe and make more accurate observations of distant celestial objects.

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13) The process in which heat flows by the mass movement of molecules from one place to another is known as
A) conduction.
B) convection.
C) radiation.

Answers

B) Convection is the process in which heat flows by the mass movement of molecules from one place to another.

Convection is the transfer of heat through the movement of fluids, such as liquids or gases. When a fluid is heated, its molecules gain energy and move faster, causing the fluid to expand and become less dense. This heated fluid rises, displacing cooler fluid, which then sinks to take its place. This creates a continuous flow, transferring heat from one location to another. An example of convection is the movement of hot air rising from a fireplace or the movement of water in a pot as it is heated on a stove. Convection is an important mechanism for heat transfer in many natural phenomena, such as weather patterns, ocean currents, and the movement of magma in the Earth's mantle.

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Consider the video tutorial you just watched. Suppose we repeat the experiment, but this time place the divider closer to one side of the tube than to the other. How will the speed of the air on the wide and narrow sides of the divider compare? (Assume that burning has a negligible effect on the mass of the air circulating through the tube.)

Answers

The speed of the air on the wide side of the divider should be greater than the speed of the air on the narrow side.

What is speed?

Speed is the rate at which an object covers a certain distance in a given period of time. It is measured in units of distance, such as kilometers per hour (km/h), miles per hour (mph), or feet per second (fps). Speed is a scalar quantity, which means it has magnitude but no direction. Speed is usually calculated by dividing the distance an object has traveled by the time it took to travel that distance. It is important to note that speed does not necessarily equal velocity, as velocity has both magnitude and direction.

This is because the amount of space on the wide side is greater than on the narrow side, allowing more air to be pushed through the tube. Therefore, the air on the wide side will move faster due to the increased pressure.

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Suppose that two objects attract each other with a gravitational force of 16 units. If the distance between the two objects is doubled, what is the new force of attraction between the two objects? (Circular Motion and Satellite Motion - Lesson 3- Universal Gravitation: Newton's Law of Universal Gravitation)

Answers

The new force of attraction between the two objects would be 4 units. This is because the gravitational force between two objects is inversely proportional to the square of the distance between them.

What is units?

Units refer to standardized measurements used to quantify the amount, size, or intensity of something. They are essential in all areas of science and engineering, allowing for comparison and communication between different people, places, and times. Units are typically based on an international standard, so that measurements are consistent worldwide. For example, a meter is the same all over the world, and a kilogram is the same everywhere. This allows for accurate measurements to be taken and communicated, no matter the location. Units are also important for engineering and construction, since they allow for precise calculations and measurements to be taken. Without them, it would be impossible to accurately build complex structures.

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81) An ideal Carnot refrigerator with a performance coefficient (COP) of 5.0 cools items inside of it to What is the high temperature needed to operate this refrigerator?
A) 61° C
B) 1395° C
C) 6° C
D) 30° C

Answers

The high temperature needed to operate the ideal Carnot refrigerator with a performance coefficient (COP) of 5.0 cools items inside of it to 30°C.

The performance coefficient (COP) of a refrigerator is defined as the ratio of the heat removed from the cold reservoir to the work done on the system. The COP of a Carnot refrigerator is given by the equation COP = Th/(Th - Tc), where Th is the high temperature and Tc is the low temperature of the refrigerator.

In this case, we are given that the COP of the refrigerator is 5.0. Let Tc be the temperature inside the refrigerator where items are cooled to. From the problem, we know that the high temperature (Th) needed to operate the refrigerator is unknown. Therefore, we can use the equation for COP to solve for Th:

COP = Th/(Th - Tc)

5.0 = Th/(Th - 20)

5.0Th - 100 = Th

4.0Th = 100

Th = 25°C + 20°C = 30°C

Therefore, the high temperature needed to operate the ideal Carnot refrigerator with a performance coefficient (COP) of 5.0 cools items inside of it to 30°C.

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Three parallel plate capacitors, each having a capacitance of 1.0 µF are connected in parallel.
The potential difference across the combination is 100 V. What is the equivalent capacitance of this combination?

Answers

Three parallel plate capacitors, each having a capacitance of 1.0 µF are connected in parallel. The potential difference across the combination is 100 V. The equivalent capacitance of the combination is 3.0 µF.

When capacitors are connected in parallel, their equivalent capacitance is the sum of individual capacitances. Therefore, the equivalent capacitance of the three 1.0 µF capacitors connected in parallel is 3.0 µF. The potential difference across the combination of capacitors is the same as the potential difference across each capacitor, which is 100 V in this case. This means that the total charge stored in the capacitors is equal to the product of the equivalent capacitance and the potential difference, which is:

Q = Ceq × V

Q = 3.0 µF × 100 V

Q = 300 µC

Thus, the equivalent capacitance of the combination of capacitors is 3.0 µF, and the total charge stored in the capacitors is 300 µC.

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one of the principle differences between a routine induction and a rapid sequence induction is that in a rapid sequence induction
T/F

Answers

True. One of the principal differences between a routine induction and a rapid sequence induction is that in a rapid sequence induction, the patient is given medications to induce sleep and paralysis.

Such as anesthetic drugs) as quickly as possible, in order to reduce the time the patient is under general anesthesia and to minimize the risk of awareness or movement during the surgical procedure. In contrast, a routine induction is a slower process that involves administering small doses of medication over a longer period of time, in order to allow the patient to fully wake up and become relaxed before being given anesthesia. The goal of a routine induction is to ensure that the patient is fully conscious and cooperative during the surgical procedure.

Therefore, the main difference between a rapid sequence induction and a routine induction is the speed and method of inducing sleep and paralysis in the patient. In a rapid sequence induction, the patient is induced quickly and with larger doses of medication, while in a routine induction, the patient is induced more slowly and with smaller doses of medication.  

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A ball is thrown with an initial velocity of 20 m/s at an angle of 60° above the horizontal. If we can neglect air resistance, what is the horizontal component of its instantaneous velocity at the exact top of its trajectory?.

Answers

Answer:

[tex]10\; {\rm m\cdot s^{-1}}[/tex].

Explanation:

Under the assumption that air resistance on the ball is negligible, gravitational pull from the Earth would be the only force acting on the ball during the flight.

The resultant force on the ball would be equal to the gravitational pull, which is entirely in the vertical direction. Thus, the net force in the horizontal direction would be [tex]0[/tex] while the ball is in the air.

By Newton's Laws of Motion, since horizontal acceleration is [tex]0[/tex] during the flight, velocity of the ball in the horizontal direction would stay unchanged in a translational equilibrium.

It is given that the ball was launched at an angle of elevation of [tex]\theta = 60^{\circ}[/tex] above the horizon. The initial velocity [tex]u[/tex] of the ball can be decomposed into two components:

Initial vertical velocity: [tex]u\, \sin(\theta)[/tex] (opposite to the angle of elevation,) andInitial horizontal velocity [tex]u\, \cos(\theta)[/tex] (adjacent to the angle of elevation.)

With [tex]u = 20\; {\rm m\cdot s^{-1}}[/tex], the horizontal velocity of the ball at launch would be [tex](20\; {\rm m\cdot s^{-1}})\, \cos(60^{\circ}) = 10\; {\rm m\cdot s^{-1}}[/tex].

Since the horizontal velocity of the ball stays unchanged during the flight, the horizontal velocity of the ball at the vertex of the trajectory would be equal to the value at launch: [tex]10\; {\rm m\cdot s^{-1}}[/tex].

a series lr circuit contains an emf source of 14 v having no internal resistance, a resistor, a 34 h inductor having no appreciable resistance, and a switch. if the emf across the inductor is 80% of its maximum value 4.0 s after the switch is closed, what is the resistance of the resistor?

Answers

To solve this problem, we can use the equation for the voltage across an inductor in a series LR circuit:

V_L = V_emf (1 - e^(-t/(L/R)))

Where V_L is the voltage across the inductor, V_emf is the emf of the source, t is the time since the switch was closed, L is the inductance, and R is the resistance.

We know that the emf source has no internal resistance, so we can assume that R is equal to the resistance of the resistor in the circuit.

At t = 4.0 s, the voltage across the inductor is 80% of its maximum value. We can use this information to solve for R:

0.8 = 1 - e^(-4.0/(34/R))

e^(-4.0/(34/R)) = 0.2

-4.0/(34/R) = ln(0.2)

R = -4.0/(34*ln(0.2))

R ≈ 22.1 ohms

Therefore, the resistance of the resistor in the series LR circuit is approximately 22.1 ohms.
In a series LR circuit, the time constant (τ) is given by the formula τ = L/R, where L is the inductance (34 H in this case) and R is the resistance of the resistor.

When the EMF across the inductor is 80% of its maximum value, the voltage across the resistor would be the remaining 20% of the total voltage (14 V). Therefore, the voltage across the resistor is 0.2 * 14 V = 2.8 V.

After 4.0 seconds, the inductor has reached 80% of its maximum EMF, so the circuit is 1 - 0.8 = 0.2 or 20% away from its steady-state condition. Using the formula V(t) = V₀ * (1 - e^(-t/τ)), where V(t) is the voltage across the resistor at time t and V₀ is the initial voltage (14 V), we can solve for τ:

2.8 V = 14 V * (1 - e^(-4.0 s / τ))

Divide both sides by 14 V:
0.2 = 1 - e^(-4.0 s / τ)

Subtract 1 and multiply by -1:
0.8 = e^(-4.0 s / τ)

Take the natural logarithm of both sides:
ln(0.8) = -4.0 s / τ

Rearrange to find τ:
τ = -4.0 s / ln(0.8)

Now, using the time constant τ and the formula τ = L/R, we can find the resistance R:

R = L / τ
R = 34 H / (-4.0 s / ln(0.8))

Solve for R:
R ≈ 15.96 Ω

The resistance of the resistor is approximately 15.96 Ω.

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if the current enters the inductor from the bottom, can you tell if the current is increasing, decreasing, or staying the same? if so, which? explain.

Answers

It is not possible to tell if the current is increasing, decreasing, or staying the same without further information. The behavior of the current in an inductor is dependent on the voltage applied across it and the magnitude of the inductance.

What is voltage?

Voltage is the electrical potential difference between two points in an electrical circuit. It is the measure of the amount of energy required to move a unit charge from one point to another. Voltage is the electrical force that causes electrons to flow through a conductor, such as a wire. Voltage is also referred to as electromotive force (EMF) or electric potential. It is measured in volts (V). When a voltage is applied to an electrical circuit, it causes a current to flow through it. Voltage is an important factor when considering electrical safety and must be properly controlled to ensure that people, animals, and objects are not exposed to dangerous levels of electricity.

If the voltage is increasing over time, then the current will also increase, and if the voltage is decreasing over time, then the current will also decrease. If the voltage is constant, then the current will remain the same.

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A charged particle is projected into a region of uniform, parallel, ® and 4 fields. The force on the particle is: A.zero B.at some angle < 90° with the field lines C.along the field lines D.perpendicular to the field lines E.unknown (need to know the sign of the charge)

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The force on the particle is: Unknown (need to know the sign of the charge).

What is force?

Force is a physical interaction that is capable of changing the motion of an object. It is a vector quantity, meaning it has both magnitude and direction. There are four fundamental forces in nature: gravitational, electromagnetic, strong nuclear and weak nuclear forces. Gravity is the force that attracts objects to one another and is the force responsible for keeping planets in orbit around the sun. Electromagnetic force is responsible for the interactions between charged particles, such as electrons and protons.

The force on a charged particle in an electric field is given by F = qE, where q is the charge of the particle and E is the electric field. Since the sign of the charge is not known, the force on the particle can not be determined.

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What is the angular speed in rad/s of an electric motor that rotates at 1.8*10³ rpm?

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The angular speed of the electric motor is 188.5 rad/s (rounded to one decimal place).

Given that the electric motor rotates at 1.8*10³ rpm (revolutions per minute), we can convert it to radians per second (rad/s) using the following formula:

angular speed = (2π × rotational speed in rpm) / 60

where 2π is the conversion factor from revolutions to radians and 60 is the number of seconds in a minute.

Substituting the given value, we get:

angular speed = (2π × 1.8 × 10³) / 60

angular speed = (3.6π × 10²) / 60

angular speed = 60π rad/s

angular speed = 188.5 rad/s (rounded to one decimal place)

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an object much more massive than jupiter, but too small to support thermonuclear fusion is called a

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An object much more massive than Jupiter, but too small to support thermonuclear fusion is called a brown dwarf.

Brown dwarfs are often referred to as failed stars because they are too small to sustain the fusion reactions that occur in the cores of true stars.

They are typically between 13 and 80 times the mass of Jupiter and can emit some heat and light from residual energy left over from their formation, but they are not able to sustain the fusion of hydrogen into helium like a true star. Instead, they slowly cool over time, eventually becoming difficult to detect with telescopes.

Hence, An object much more massive than Jupiter, but too small to support thermonuclear fusion is called a brown dwarf.

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an ideal gas is expanded at constant temperature. what are the signs ( , -, or 0) of deltah, deltas, and deltag for this system?

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For an ideal gas expanding at constant temperature, the internal energy and enthalpy of the system remain constant.

Therefore:

ΔH (change in enthalpy) = 0

ΔS (change in entropy) > 0,

because the gas is expanding and becoming more disordered, increasing the entropy of the system

ΔG (change in free energy) = ΔH - TΔS.

Since ΔH = 0 and ΔS > 0, ΔG < 0.

This means that the process is spontaneous, and the system releases free energy as it expands.

In summary, ΔH = 0, ΔS > 0, and ΔG < 0.

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suppose that during a thunder-storm you hear a clap of thunder 6.33 seconds after you see a lightning strike. how far away are you from the lightning strike? assume room temperature air. assume light travels so fast that you see the lightning nearly instantaneously.

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The speed of sound in room temperature air is approximately 343 meters per second. Therefore, to calculate the distance from the lightning strike, we can use the equation:

distance = speed of sound x time

In this case, the time is 6.33 seconds.

distance = 343 m/s x 6.33 s = 2171.19 meters

Therefore, you are approximately 2171.19 meters (or 2.17 kilometers) away from the lightning strike.

To determine how far away you are from the lightning strike, you'll need to consider the speed of sound in air. At room temperature (20°C or 68°F), the speed of sound is approximately 343 meters per second (1,125 feet per second). Since you hear the thunder 6.33 seconds after seeing the lightning, you can calculate the distance using the formula:

Distance = Speed of Sound × Time

Distance = 343 m/s × 6.33 s

Distance ≈ 2,170 meters (7,119 feet)

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What style of differential does not vary the amount of torque sent to the wheels?.

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The style of differential that does not vary the amount of torque sent to the wheels is called a locked or spooled differential.

A locked or spooled differential mechanically connects both wheels on an axle, so that they rotate at the same speed regardless of the traction available to each wheel. This means that the torque is evenly distributed to both wheels, without any variation.

Locked or spooled differentials are often used in off-road vehicles, drag racing cars, and other high-performance applications where maximum traction and power delivery are needed. However, they can make the vehicle less maneuverable in tight turn and can cause excessive tire wear and damage if used on paved roads for extended periods of time.

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At what speed does ketchup exit the iconic heinz ketchup glass bottle?. 028 mph.

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The average speed at which ketchup exits the Heinz ketchup glass bottle is approximately 0.028 m/s.

The viscosity of ketchup is high, which makes it difficult to flow out of the bottle. A study conducted by researchers at MIT found that the average speed at which ketchup exits the bottle is around 0.028 m/s.

This is slower than other liquids, such as water or oil, due to the complex structure of ketchup and the way its particles interact with each other.

The study also found that tapping the bottom of the bottle can help to speed up the flow of ketchup by breaking up the structure and allowing it to flow more freely.

The complete question is:
What is the average speed of the iconic Heinz ketchup as it exits the glass bottle?

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A uniform magnetic field passes through two areas, A1 and A2. The angles between the magnetic field and the normals of areas A1 and A2 are 30.0[infinity] and 60.0[infinity], respectively. If the magnetic flux through the two areas is the same, what is the ratio A1/A2?
A) 0.354
B) 0.866
C) 1.00
D) 1.23
E) 1.73

Answers

A uniform magnetic field passes through two areas, A1 and A2. The angles between the magnetic field and the normals of areas A1 and A2 are 30.0[infinity] and 60.0[infinity], respectively. If the magnetic flux through the two areas is the same, the ratio A1/A2 is 0.866.

The magnetic flux through an area A can be given as
Φ = B * A * cos(θ),
where B is the magnitude of the magnetic field, θ is the angle between the magnetic field and the normal of the area A.Since the magnetic flux is the same through both areas, we have:
B * A1 * cos(30°) = B * A2 * cos(60°)
Simplifying this expression, we get:
A1/A2 = cos(60°)/cos(30°) = 0.866. Therefore, the ratio A1/A2 is 0.866.

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A plane has an airspeed of 142 m/s. A 56.0 m/s wind is blowing southward at the same time as the plane is flying. If the velocity of the plane relative to the ground is directly eastward, what is the magnitude of that velocity?

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To find the magnitude of the velocity of the plane relative to the ground, we need to use vector addition. The plane's velocity relative to the ground will be the sum of its airspeed and the velocity of the wind blowing southward.

Since the plane is flying directly eastward, we can split its velocity into two components: a north-south component (which will be affected by the wind), and an east-west component (which will remain constant).

To find the north-south component of the plane's velocity, we can use trigonometry. The angle between the plane's velocity and the north-south axis is 90 degrees (since it's flying directly eastward), so we can use the sine function:

sin(theta) = opposite/hypotenuse

In this case, the opposite side is the north-south component of the plane's velocity, and the hypotenuse is the airspeed of the plane. So we have:

sin(90) = north-south velocity/142

Solving for the north-south velocity, we get:

north-south velocity = 142

So the north-south component of the plane's velocity is 142 m/s.

Now we need to add the velocity of the wind blowing southward. Since the wind is blowing directly southward, its velocity has no east-west component. So the velocity of the plane relative to the ground will have an eastward component of 142 m/s (which is the same as the plane's airspeed) and a southward component of 56 m/s (which is the velocity of the wind).

To find the magnitude of the velocity, we can use the Pythagorean theorem:

velocity^2 = (142)^2 + (56)^2

Solving for the velocity, we get:

velocity = sqrt[(142)^2 + (56)^2]

velocity = 152.6 m/s

So the magnitude of the velocity of the plane relative to the ground is 152.6 m/s.

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