Answer:
(a) the gravitational influence on visible matter can not be explained by matter that can be seen.
A student did 24 J of work on a chair. She applied a force of 12 N and moved the chair 2 m. What else do you need to know to determine the amount of power used?
Answer:
time
Explanation:
power = work done ÷ time
Please give an answer that is coherent
A ceiling fan operates at three speeds, using 120 V of electricity from the wall. At low speeds, it uses 0.25 A. Calculate the resistance needed to generate that current. Then in 1-2 sentences, describe how the resistance would change at medium and high speeds if larger currents are needed at those speeds. Your answer should include the calculated resistance and a sentence describing your reasoning.
Answer:
480
Explanation:
resistance equals to potential difference divide by electric current
120÷0.25
=480
Answer:
[tex]\mathsf {480 \Omega}[/tex]
Explanation:
[tex]\textsf {Formula used for calculating resistance :}[/tex]
[tex]\mathsf {Resistance = \frac{Voltage}{Current} }[/tex]
[tex]\textsf {This is otherwise known as Ohm's Law, hence the unit of resistance.}\\[/tex]
[tex]\textsf {Solving :}[/tex]
[tex]\implies \mathsf {R = \frac{120}{0.25}}[/tex]
[tex]\implies \mathsf {R = 480\Omega}[/tex]
[tex]\textsf{If the fan uses higher current at higher speeds, then}\\\textsf{the resistance would decrease as it is inversely}\\\textsf {proportional to the current.}[/tex]
A child, m = 25. 0 kg, swings from a rope, l = 9. 43 m, which hangs above water, d = 1. 9 m, when vertical. The child is h = 4. 8 m above the water when she begins to swing.
The velocity at the bottom of the swing is [tex]\mathbf{v= \sqrt{2gh -2gd}}[/tex]. The time it took the child to reach the river is 0.62 seconds.
The objective of this question is to determine:
The expression for the velocity of the child at the bottom of the swing.Suppose the child lets go at the bottom of the swing, how long does she take to reach the river at t seconds.At the bottom of the swing, there is an equal change in both the Kinetic energy as well as the potential energy and the expression can be computed as:
[tex]\mathbf{\dfrac{1}{2}mv^2 = mg (h -d)}[/tex]
[tex]\mathbf{\dfrac{v^2}{2}= g (h -d)}[/tex]
[tex]\mathbf{v^2= 2gh -2gd}[/tex]
[tex]\mathbf{v= \sqrt{2gh -2gd}}[/tex]
According to the second equation of motion;
[tex]\mathbf{S = ut +\dfrac{1}{2}at^2}[/tex]
where;
distance s = d = 1.9 macceleration due to gravity = 9.8 m/s²initial velocity (u) = 0∴
[tex]\mathbf{1.9 = 0(t) +\dfrac{1}{2}(9.8) t^2}[/tex]
[tex]\mathbf{1.9 = \dfrac{1}{2}(9.8) t^2}[/tex]
[tex]\mathbf{t^2 =\dfrac{1.9\times 2}{9.8} }}[/tex]
[tex]\mathbf{t = \sqrt{\dfrac{1.9\times2}{9.8}}}[/tex]
[tex]\mathbf{t =0.62 \ s}[/tex]
Therefore, we can conclude that the velocity at the bottom of the swing is [tex]\mathbf{v= \sqrt{2gh -2gd}}[/tex]. The time it took the child to reach the river is 0.62 seconds.
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A 25 kg chair initially at rest on a horizontal floor requires a 165 N horizontal force to set it in motion. Once the chair is in motion, a 127 N horizontal force keeps it moving at a constant velocity.
Find the coefficient of static friction between the chair and the floor.
b. Find the coefficient of kinetic friction between the chair and the floor.
a. The coefficient of static friction between the chair and the floor is 0.67.
b. The coefficient of kinetic friction between the chair and the floor is 0.52.
Given the following data:
Mass of chair = 25 kgHorizontal force A = 165 NHorizontal force B = 127 NScientific data:
Acceleration due to gravity = 9.8 [tex]m/s^2[/tex]a. To find the coefficient of static friction between the chair and the floor:
Mathematically, the force of static friction is given by the formula;
[tex]F_s = uF_n = umg[/tex]
Where;
Fs represents the force of static friction.μ represents the coefficient of static friction.[tex]F_n[/tex] represents the normal force.g is the acceleration due to gravity.mμ is the mass of an object.Making μ the subject of formula, we have:
[tex]u=\frac{F_s}{mg}[/tex]
Substituting the given parameters into the formula, we have;
[tex]u=\frac{165}{25 \times 9.8} \\\\u=\frac{165}{245}[/tex]
μ = 0.67
b. To find the coefficient of kinetic friction between the chair and the floor:
Note: The normal force would be the same as above.
[tex]u_k = \frac{F_k}{F_n} \\\\u_k = \frac{127}{245}\\\\u_k =0.52[/tex]
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help -----------------------------------------
Answer:
H,G,E,D,C,B,A,I,F
Explanation:
F is an ignious intrusion and I cross cuts H to A so it must be newer.
A car starts from rest and accelerates at 2.5m/s^2 for 2s. What is the final velocity of the car
Answer:
5m/s ez
Explanation:
plz make me brainliest
Does a 2-kilogram rock have twice the mass
of a 1-kilogram rock?
Yes.
Because the mass would be measured in kilograms ( given units) 2 is two times greater than 1, so it would have twice the mass
Answer:
yes the 2 kg rock would be twice the size as a 1 kg rock
Work is required to lift a barbell. How many times more work is required to lift the barbell 2 times as high
Answer:
2 time
Explanation:
when distance double the work double
During a collision, a 63.9-kilogram driver of a car moving at 24 m/s is brought to rest by an inflating airbag in 1.2 seconds. What is the magnitude of the force exerted on the driver by the airbag?
Hi there!
We can use impulse for this situation:
I = Δp = mΔv
Impulse = Force × time, so:
I = 63.9(24) = 1533.6 Ns
Find force by dividing by time:
I/t = 1533.6/1.2 = 1278 N
How does the electric energy between two negativly charged particles change if one particles charge is increased by a factor of 2
Answer:
i dont know this one
Explanation:
sorry i wish i could help but if u look closley on that qyestion you will understand it mor
The mercury in a barometer of a cross-sectional area 1 cm² stands at 75 cm, and the space above it is 9 cm in length. What
volume of air, measured at 3. The mercury in a barometer of a cross-sectional area 1 cm² stands at 75 cm, and the space above it is 9 cm in length. What
volume of air, measured at atmospheric pressure, would have to be admitted into the space to cause the column of the mercury
to drop to 59 cm?
The ideal gas equation and the pressure in barometer allows us to find the amount of air that we must introduce into the barometer for the change in height of the mercury column is:
The variation of the volume is: ΔV = 7.67 cm³
Pressure is defined by the relationship between force and area.
P = F / A
The ideal gas equation establishes a relationship between pressure, volume, and temperature of an ideal gas.
PV = nR T
Where P is pressure, V is volume, and T is temperature.
Let's write this equation for two points assuming that the temperature has not changed.
P₀ V₀ = P₁ V₁
V₁ = [tex]\frac{P_o}{P_1} \ V_o[/tex] (1)
The subscript "o" is used for the start point and the subscript "1" for the end point.
The pressure in a barometer is:
P = ρ g y
They indicate the initial height of the barometer y₀=75 cm, the distance from empty space y'₀ = 9 cm and the final height of the barometer y₁ = 59 cm.
The volume of the cylinder is
V = π r² y
Let's calculate the initial volume.
V₀ = π 1 9
V₀ = 28.27 cm³
We substitute in equation 1.
V₁ = [tex]\frac{\rho \ g \ y_o}{\rho \ g \ y_1} \ V_o[/tex]
V₁ = [tex]\frac{y_o}{y_1} \ V_o[/tex]
Let's calculate.
V₁ = [tex]\frac{75}{59} \ 27.27[/tex]
V₁ = 35.94 cm³
The volume to be incremented is
ΔV = V₁ - V₀
ΔV = 35.94 - 28.27
ΔV = 7.67 cm³
Using the ideal gas equation and the pressure in barometer we can find the amount of air that we must introduce into the barometer for the change in height of the mercury column is:
The change of the volume is: ΔV = 7.67 cm³
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what is Secular Music's instrument's?
Answer:
Drums, harps, recorders, and bagpipes.
Explanation:
An object is at rest. There are several forces acting on the object, but the net force is zero. If all the
forces acting on the object were to suddenly double in size, would the object start moving? Why or why not?
Answer:
no
Explanation:
because the heaver an object the harder it is to move s the force will not be able to move it
What is the instruments used to measure light intensity, wind intensity and relative humidity
Answer:
we use : photometer to measure light intensity
:Anemometer to measure wind intensity
:Hygrometer to measure relative humidity
a race car traveling at 44m/s slows at a constant rate to a velocity of 22m/s over 11 seconds , how far does it move during this time
find distance and acceleration
FAST PLEASE !!
Answer:
-1.2×10^2 m
I hope this helps you
The angular quantities L, omega, and alpha are vectors. The vectors point along the axis of rotation with a direction determined by __________.
The vectors point along the axis of rotation with a direction determined by an arrow.
What is a vector?There are two types of physical quantity one is a scaler and another one is a vector.
The quantity that requires only megnitude to define is known as the scalar quantity. While the vector quantities need both megnitude and the direction to define.
The vector quantity is represented by an arrow. The vectors point along the axis of rotation with a direction determined by an arrow.
The angular quantities L, omega, and alpha are vector quantities.
Hence arrow is the correct answer for the blank.
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The direction of the vectors of angular momentum and L, angular velocity omega and the mass alpha is determined using the right hand rule.
What is right hand rule?Righthand rule in physics states that, when we curl our right hand fingers, the direction of the angular momentum and velocity will be in the direction of thumb and curl of fingers determine the axis of rotation.
Angular momentum is a vector quantity defined as the product of moment of inertia and angular velocity where, the angular velocity ω is the rotational analogue of linear velocity i.e.. product of the linear velocity and radius of rotational path.
Therefore, the angular quantities L, angular velocity ω along the axis of rotation can be determined using the right hand rule. Where direction of thump represents the direction of vector components.
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When the atmosphere is absolutely unstable, the environmental lapse rate is ________ the dry adiabatic lapse rate.
Answer: greater than
Explanation:
in terms of the wavelength of the sound wave, about how far below the open end of the resonance tube is the first resonant position?
The first resonant position below the open end of the resonance tube is; one-quarter of the wavelength
In the event of the first resonant position in a resonance tube, there will be a maximum air displacement which is only one antinode right at the open end where the motion is constrained.
However, there will be no displacement at the closed end which means another one node right at the closed end where air is halted.
This means that the standing wave will have one-quarter of the wavelength in the test tube.
Thus;
L = ¼λ
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b. Ron bicycles forward with an acceleration of 2.1 m/s2. If he is applying a forward force of 195 N, what is his mass?
Answer:
92.86 kgExplanation:
lThe mass of an object given only it's force and acceleration can be found by using the formula
[tex]m = \frac{f}{a} \\ [/tex]
f is the force
a is the acceleration
From the question
f = 195 N
a = 2.1 m/s
We have
[tex]m = \frac{195}{2.1 } = 92.857142... \\ [/tex]
We have the final answer as
92.86 kgHope this helps you
At about 1 second after the beginning of the universe, one type of particle was able to start traveling freely through the universe. These particles are still with us, but they are extremely hard to detect. They are called:
The Big Bang theory allows finding the result for which particles were formed in the 1 s of the universe is:
The quark subatomic particles were the first to form due to the high amount of energy.
The Big Bang theory says that the universe is formed about 14 billion years ago, of a structure that is very high energy.
Einstein's equation establishes the relationship between energy and matter, establishing that energy can be converted into matter.
E = m c²
Where E is energy, m is mass, and c is the speed of light.
In the 1 s of the universe the energy density was so high that all subatomic particles were formed, the first being quarks.
When the universe cooled enough, the quarks combined to form protons and neutrons, from which atoms were formed.
In conclusion, using the Big Bang theory we can find the result for which particles were formed in the 1 s of the universe is:
The quark subatomic particles were the first to form due to the high amount of energy.
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When astronomers carefully examine the planets found by Kepler and draw conclusions from the Kepler sample, what do they conclude about planets the size (radius) of Earth
Given what we know about the Kepler space program, we know that the astronomers discovered that Earth-sized planets are more common than we imagined.
Kepler was launched with the intention of getting a closer look at other planets outside of our solar system using enhanced photometrics.
The idea behind this launch was to discover more Earth-sized planets, preferably within the habitable zone of their central star.
What this mission showed astronomers, is that Earth-sized planets are more common than we could have imagined, Kepler proved this by finding over 2,662 planets to date.
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when light reflects from a surface, there is a change in its
When light reflects from a surface, there is a change in its intensity. Thus, the correct option is C.
What is Light intensity?Light intensity is also known as luminous intensity. It is the amount of light which is falling on a surface over any given square foot or square meter in size. Light intensity can be measured in terms of lumens per square foot (foot candles) or lumens per square meter (lux).
Light intensity is affected by various factors such as surface on which the light rays strike, the medium, reflection, and the refraction of light.
When a ray of light reflects from a surface, there is a change in the intensity of light and also the speed of light in that medium.
Therefore, the correct option is C.
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Your question is incomplete, most probably the complete question is:
When light reflects from a surface, there is a change in its:
a. frequency
b. velocity
c. intensity
d. phase
when you hold a spherical concave mirror with a 48.2-cm radius of curvature in front of your face, you see an image of your face that is 61.8 cm in front of the mirror. what is the distance between the mirror and your face?
The distance between the mirror and your face is 39.5 cm
Using the mirror formula 2/r = 1/u + 1/v where r = radius of curvature = - 48.2 cm, u = distance between mirror and your face = object distance and v = distance between image and your face = - 61.8 cm. The distances are negative since the image is in front of the mirror and distances to the left of the mirror are negative.
So, making u subject of the formula, we have
2/r = 1/u + 1/v
1/u = 2/r - 1/v
1/u = (2v - r)/rv
u = rv/(2v - r)
Substituting the values of the variables into the equation, wse have
u = -48.2 cm × -61.8 cm/(2 × -61.8 cm - (-48.2 cm))
u = 2978.76 cm²/(-123.6 cm + 48.2 cm)
u = 2978.76 cm²/-75.4 cm
u = -39.51 cm
u ≅ -39.5 cm (The distance is negative since it is in front of the mirror)
So, the distance between the mirror and your face is 39.5 cm
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the free body diagram shown above is for a 5 kg box on a rough surface being pulled to the right at a constant speed by a string that is at an angle of 30° above the horizontal. the coefficient of kinetic friction between the box and the surface is 0.30. the tension in this string is most nearly:
The tension in the string pulling the box is most nearly 17 N.
The given parameters;
mass of the box, m = 5 kginclination of the string, θ = 30°coefficient of kinetic friction, μ = 0.3The tension on the string is calculated by applying Newton's second law of motion as follows.
[tex]\Sigma F = ma[/tex]
at constant speed, acceleration, a, = 0
[tex]\Sigma F = 0\\\\T_x - \mu F_n = 0\\\\Tcos(\theta) - \mu F_n = 0\\\\Tcos(\theta)= \mu F_n\\\\T = \frac{\mu F_n}{cos(\theta)} \\\\T = \frac{0.3 \times 5 \times 9.8}{cos(30)} \\\\T = 16.97 \ N\\\\T \approx 17 \ N[/tex]
Thus, the tension in the string pulling the box is most nearly 17 N.
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Dark matter is inferred to exist because it explains the abundance of helium in the universe today. we can observe its gravitational influence on visible matter. it explains how the expansion of the universe can be accelerating. we see lots of dark patches in the sky
we can observe its gravitational influence on visible matter.
Dark matter is a term used in astrophysics to refer to matter that corresponds to approximately 80% of the matter in the universe.
Dark matter is related to the motion of galaxies because visible matter makes up only a small part of the cluster and the galaxies show signs of being composed mainly of a halo of dark matter concentrated in their center.
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Daniel is 50.0 meters away from a building. He observes that his line-of-sight to the tip of the building makes an angle of 63.0° with the horizontal. What is the height of the building?
Answer:
willie tower
Explanation:
mataas kasi
When we use an analogy that represents the expanding universe with the surface of an expanding balloon, what does the inside of the balloon represent?
Answer: When we use an analogy that represents the expanding universe with the surface of an expanding balloon, what does the inside of the balloon represent? The inside of the balloon does not represent any part of our universe.
The first observation of block oscillation was in a semiconductor superlattice with period 10nm.
Answer:How did family life under Prince Shotoku’s rule reflect Confucian ideals?
Women had rights and were equal to their husbands.
Children were taught to value individualism over community.
People were expected to give up worldly concerns and turn to nature.
Households were structured to maintain order, with the husband as head.
Explanation:
An escalator in a busy shopping centre lifts people up from one floor to another. This takes 1.2 MJ every minute. What is the power output of the escalator motor? Give your answer in kW.
An escalator that takes 1.2 MJ every minute has a power output of 1200 kW.
An escalator used to lift people up from one floor to another, exerts a work (w) of 1.2 MJ in 1 minute (t).
In physics, power (P) is the amount of energy (w) transferred or converted per unit time (t).
[tex]P = \frac{w}{t} = \frac{1.2 \times 10^{6} J }{1min} = 1.2 \times 10^{6} W[/tex]
We can convert 1.2 × 10⁶ W to kW using the conversion factor 1 kW = 1000 W.
[tex]1.2 \times 10^{6} W \times \frac{1kW}{1000W} = 1200kW[/tex]
An escalator that takes 1.2 MJ every minute has a power output of 1200 kW.
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A moving object is in equilibrium. Which best describes the motion of the object if no forces change?
It will change directions.
It will slow down and stop.
It will maintain its state of motion.
It will speed up and then slow down.
Answer:
it is It will maintain its state of motion. because of newtons law states that any object in morion will stay in motion unless acted upon another force pushing against it
Explanation:
Answer:
It will maintain its state of motion.
Explanation:
