PLEASE HELP!! URGENT!!

Answer: A controlled experiment is a scientific test done under controlled conditions, meaning that just one (or a few) factors are changed at a time, while all others are kept constant. In some cases, there is no good way to test a hypothesis using a controlled experiment  I hope this helps you

Explanation:

Answer:

The answer is radio waves

Complete Question:

an object on a number line moved from x = 12 m to x = 124 m and moved back to x = 98 m. the time interval for all the motion was 10 s. what was the average velocity of the object?

Answer:

v = 8.6 m/s

Explanation:

       [tex]v_{avg} =\frac{x_{f} -x_{o}}{t_{f} - t_{o} } (1)[/tex]

       [tex]v_{avg} =\frac{x_{f} -x_{o}}{t_{f} - t_{o} } =\frac{98 m -12 m}{10.0 s - 0 s } = \frac{86m}{10.0s} = 8.6 m/s (2)[/tex]

Answer:

radio waves

Explanation:

Radio waves are used for communication such as television and radio. Radio waves are transmitted easily through air. They do not cause damage if absorbed by the human body, and they can be reflected to change their direction. These properties make them ideal for communications.

Answer:

The answer is radio waves.

Explanation:

I took AP EX quiz.

Answer:

a. 4.733 × 10⁻¹⁹ J = 2.954 eV b i. yes ii. 0.054 eV = 8.651 × 10⁻²¹ J

Explanation:

a. Find the energy of the incident photon.

The energy of the incident photon E = hc/λ where h = Planck's constant = 6.626 × 10⁻³⁴ Js, c = speed of light = 3 × 10⁸ m/s and λ = wavelength of light = 420 nm = 420 × 10⁻⁹ m

Substituting the values of the variables into the equation, we have

E = hc/λ

= 6.626 × 10⁻³⁴ Js × 3 × 10⁸ m/s ÷ 420 × 10⁻⁹ m

= 19.878 × 10⁻²⁶ Jm  ÷ 420 × 10⁻⁹ m

= 0.04733 × 10⁻¹⁷ J

= 4.733 × 10⁻¹⁹ J

Since 1 eV = 1.602 × 10⁻¹⁹ J,

4.733 × 10⁻¹⁹ J = 4.733 × 10⁻¹⁹ J × 1 eV/1.602 × 10⁻¹⁹ J = 2.954 eV

b. i. Is this energy enough for an electron to leave the atom

Since E = 2.954 eV is greater than the work function Ф = 2.9 eV, an electron would leave the atom. So, the answer is yes.

ii. What is its  maximum energy?

The maximum energy E' = E - Ф = 2.954 - 2.9

= 0.054 eV

= 0.054 × 1 eV

= 0.054 × 1.602 × 10⁻¹⁹ J

= 0.08651  × 10⁻¹⁹ J

= 8.651 × 10⁻²¹ J

Answer:

[tex]X=3976.078202kW \approx 3976kW[/tex]

Explanation:

From the question we are told that

Wind speed[tex]V_w=10m/s[/tex]

Turbine blade diameter [tex]D=90m[/tex]

Air density  [tex]\tau=1.25kg/m^3[/tex]

Mechanical energy [tex]K.E =0.05kJ/kg[/tex]

Generally the power generation potential of the wind turbine X is mathematically given as

  [tex]X=m'*K.E[/tex]

Where

[tex]m'=\tau *\pi*D^2/4*V[/tex]

[tex]m'=1.25 *\pi*90^2/4*10[/tex]

[tex]m'=79521.56404kg/s \approx 79521.5kg/s[/tex]

Therefore

[tex]X=m'*K.E[/tex]

[tex]X=79521.56404*0.05[/tex]

[tex]X=3976.078202kW \approx 3976kW[/tex]

[tex]X=4.0MW[/tex]

Answer: 200 joules I think.

Explanation:

"The theory of low-mass star formation, which is well-supported by observation, suggests that low-mass stars form by the gravitational collapse of rotating density enhancements within molecular clouds."

Answer:

The current theoretical explanation of how stars form that they are formed by some type of gravitational collapse of rotating density enhancements within the molecular clouds.

Hope this helped!

P.S I used the notes my teacher gave me since we are learning about this.

Have a supercalifragilisticexpialidocious day!

Answer:

It contains approximately 14,568.7 square meters

Explanation:

Area Units Conversion

There are several units to express the area of a shape:

[tex]cm^2,\ m^2,\ km^2,\ ft^2,\ in^2,\ acres, \ hectares[/tex]

The process of expressing the area from one unit to the other is called a conversion.

Specifically, we are interested in converting from acres to square meters. The rule to make the conversion is:

[tex]1 acre = 4,046.86\ m^2[/tex]

The plot of land has 3.6 acres, thus its area is:

[tex]3.6 * 4046.86 =14,568.696\ m^2[/tex]

It contains approximately 14,568.7 square meters

Answer:

the relationship is scalar, it is independent of the specific reference system

The statement is false

Explanation:

When the concepts of work and energy are being used, a reference system must be defined to perform the calculations,

in the case of work it is defined by the relation

          W = F. d

where the point represents the scalar product, therefore the work is a scalar magnitude, it has only modulus for which any reference system is selected since the result is independent of the direction of the force, only the projection of the force depends in the given direction.

For the part of the energy it therefore has two main forms, kinetic energy and potential energy.

For kinetic energy the expression is

         K = ½ m v²

therefore, the energizes only depends on the speed module and any reference system, since it will be selected

for gravitational and elastic power energy. It does not depend on the specific value at the point but on the difference with respect to an arbitrarily defined zero, therefore, as the difference is constant, it is independent of the reference system used.

In conclusion, since the relationship is scalar, it is independent of the specific reference system, so we can select several reference systems

Answer:

a. 3.45 kHz b. 5 cm c. 7.5 cm

Explanation:

a. What is the frequency of the tuning fork?

For a tube open at both ends, the frequency, f = nv/2L. The smallest frequency at the smallest length of air column, L = 5 cm = 0.05 m is the fundamental frequency and there, n = 1 and v = speed of sound in air = 345 m/s.

So, f = v/2L

So, f = 345 m/s/(2 × 0.05 m)

= 345 m/s ÷ 0.1 m

= 3450 Hz

= 3.45 kHz

b. What is the value of L for the second resonant position?

The second resonant frequency is f' = 2f

= 2 × 3450 Hz

= 6900 Hz

Since f = nv/2L and f' = second resonant frequency when n = 2.

So, f' = 2v/2L

f' = v/L

L = v/f'

= 345 m/s ÷ 6900 Hz

= 0.05 m

= 5 cm

c. What is the value of L for the third resonant position?

The third resonant frequency is f" = 3f

= 3 × 3450 Hz

= 10350 Hz

Since f = nv/2L and f" = third resonant frequency when n = 3.

So, f" = 3v/2L

2f' = 3v/L

L = 3v/2f'

= 3 × 345 m/s ÷ (2 × 6900 Hz)

= 1035 m/s ÷ 13800 Hz

= 0.075 m

= 7.5 cm

a)The frequency of the tuning fork will be 3.45 kHz.

b) The value of L for the second resonant position will be 5 cm.

c) The value of L for the third resonant position will be 7.5 cm.

Frequency is defined as the number of repetitions of a wave occurring waves in 1 second.

The tuning fork's frequency for a tube with both ends open is;

f = nv/2L

f = 345 m/s/(2 × 0.05 m)

f= (345 m/s) / (0.1 m)

f= 3450 Hz

f= 3.45 kHz

f' = 2f is the second resonant frequency.

f'= 2 × 3450 Hz

f'= 6900 Hz

f = nv/2L

For n=2,

f' = 2v/2L

f' = v/L

The value of L for the second resonant position;

L = v/f'

L= 345 m/s ÷ 6900 Hz

L= 0.05 m

L= 5 cm

f' = 3f is the third resonant frequency.

f' = 3 × 3450 Hz

f'= 10350 Hz

f = nv/2L

For, n = 3.

f' = 3v/2L

2f' = 3v/L

The value of L for the third resonant position;

L = 3v/2f'

L=( 3 × 345 m/s)/(2 × 6900 Hz)

L= 1035 m/s / 13800 Hz

L= 0.075 m

L= 7.5 cm

Hence,The frequency of the tuning fork,value of L for the second resonant position and value of L for the third resonant position will be 3.45 kHz. 5 cm and 7.5 cm respectively.

To learn more about the frequency refer to the link;

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Answer:

Impulse = 0.9408Ns

Explanation:

Impulse is the product of force and time

Impulse = Ft

Given

Force F = mg

F = 12(9.8)

F = 117.6N

Time = 8 * 10^-3 = 0.008s

Get the impulse

Impulse = 117.6*0.008

Impulse = 0.9408Ns

Answer:

Force

Explanation:

Answer is given below

Explanation:

given data

pressure = double

volume = constant

solution

As we know that an Average velocity and rms velocity is directly proportional to square root of PV ..................1

so if we take P is doubled while keeping V constant

than Velocity increases by a factor [tex]\sqrt{2}[/tex]  

so that Factor = 1.414 for both the cases

Answer: Taxpayers

Explanation:

Taking alcohol before driving or while driving is dangerous and has resulted in lots of accidents and deaths. Alcohol tampers with the normal functioning of the brain, and also impairs ones reasoning.

Alcohol impaired driving cases handled by government officials are paid for by the taxpayers. A tax is the levy that the people in the country pays. Those funds are used in handling different government objectives and this is one of such ways.

Answer:

justin

Explanation:

justin

Answer:

Because Physics is mainly composited of math

Explanation:

If you really think about it the only way any science works is off maths, whether that be measuring the amount of NaOH to put into a solution or determening the amount of sugar you want in a cake it all relys on maths

Answer: Choice B) You would weigh less on planet A because it has less mass than  planet B.

=====================================================

Explanation:

Weight is due to the force of gravity. The higher the force of gravity, the more pull and therefore the larger weight.

Imagine that gravity was basically a rope pulling a person down. The higher the force of gravity, the stronger the pull on the rope.

Due to planet A having less mass compared to planet B, this means the force of gravity on planet A is smaller, and therefore a person on planet A will weigh less compared to planet B.

-------------

As a more real world example, the moon's mass is less than the Earth's mass. It turns out that weights on the moon are roughly 1/6 of what they would be on Earth. This means that if a person weighed 180 pounds on Earth, then they would weigh about 180*(1/6) = 180/6 = 30 pounds on the moon. This is why astronauts on the moon are able to jump higher and have a bigger bounce in their step, even if they aren't even trying to jump so high.

Answer:

convert thermal energy into mechanical energy

Explanation:

Thermodynamics generally deals with the energy changes in chemical reactions and how its affect or its influence of energy on those changes. It is widely known to be a branch of physics. It deals mainly on heat transfer processes whereby energy in the form of heat is converted into work. It simply covers or the study of energy flow in the world as a whole and the flow relationship to work, heat, the different forms of energy, and entropy.

Thermodynamics is a branch of physics that deals with the study of energy and its transformations in systems, including the transfer of heat and work. The thermodynamic processes that occur in nature convert thermal energy into mechanical energy, lead to a more ordered state, and cannot be reversed.

These processes are governed by the laws of thermodynamics, which describe the behavior of energy in various systems. The conversion of thermal energy into mechanical energy occurs through processes such as combustion, where heat is generated and used to perform work.

Natural processes tend to increase the overall order or organization in a system, known as an increase in entropy. While energy can be converted and transferred, the total energy within a closed system remains constant due to the law of energy conservation.

Therefore, the thermodynamic processes that occur in nature convert thermal energy into mechanical energy, lead to a more ordered state, and cannot be reversed.

For more details regarding thermodynamics, visit:

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Answer: Corpuscular.

Explanation:

There is a theory called the Corpuscular Theory of Light, which says that light is made of small particles called "corpuscles".

But as we know, light has a duality associated to it (it behaves like a wave and like a particle), and here is where one of the largest problems of this theory appears, because it does not explain things like diffraction or interference.

Then the correct option is corpuscular.

Answer:

hes right

Explanation:

Answer:

m = 2.2 x 10⁻⁴ kg = 0.22 g

Explanation:

The surface tension of water is 0.072 N/m. So in order for the bug to avoid sinking, its weight per unit length of contact must be no more than the surface tension of water. Therefore,

[tex]Weight\ of bug\ per\ unit\ length = Surface\ Tension\ of\ Water\\\frac{mg}{L} = Surface\ Tension\ of Water\\m = \frac{(Surface\ Tension\ of\ Water)(L)}{g}[/tex]

where,

m = mass of bug = ?

g = acceleration due to gravity = 9.81 m/s²

L = Contact length = (contact length of each leg)(No. of Legs) = (5 mm)(6)

L = 30 mm = 0.03 m

Therefore,

[tex]m = \frac{(0.072\ N/m)(0.03\ m)}{9.81\ m/s^{2}} \\[/tex]

m = 2.2 x 10⁻⁴ kg = 0.22 g

Answer:

Answer: (A) 0.75 m/s^2

Explanation:

The Second Newton's law states that an object acquires acceleration when an external unbalanced net force is applied to it.

That acceleration is proportional to the net force and inversely proportional to the mass of the object.

It can be expressed with the formula:

[tex]\displaystyle a=\frac{F_n}{m}[/tex]

Where

Fn = Net force

m  = mass

The ice skater pushes against a wall with a force of 59 N. The wall returns the force and the skater now has a net force of Fn=59 N that makes him accelerate. Being m=79 kg the mass of the skater, the acceleration is:

[tex]\displaystyle a=\frac{59}{79}[/tex]

[tex]a = 0.75\ m/s^2[/tex]

Answer: (A) 0.75 m/s^2

Answer:

a mistake

Explanation:

Answer:

Answer is explained in the explanation section below.

Explanation:

It can be determined by the use of Fourier's law of heat conduction.

Fourier's Law of Heat Conduction: States that, the rate of heat transfer is directly proportional to the temperature change from higher temperature to lower temperature. And it is directly proportional to the area perpendicular to the direction of the heat flow.

Through this statement, we can write the equation of the Fourier's law:

Q = Rate of Heat transfer.

A = Area

dT = Change in Temperature from Higher to Lower = T1 - T2, where T1 is assumed to be higher temperature.

dx = thickness of the wall, through which heat is transferring.

So,

Q is directly proportional to Area perpendicular to the direction of the heat flow.

So, we can write:

Q [tex]\alpha[/tex] A

And

Q is directly proportional to temperature change.

So, we can write

Q [tex]\alpha[/tex] dT/dx

So, in order to remove the proportionality sign, we need to introduce a constant, which is ( -K) here, Thermal conductivity material of the plane wall.

So,

Q  = - K.A . dT/dx

or

Q = - K . (H.W) . (T1-T2)/L

where, H = height of the wall

W = width of the wall

L = length of the wall.

So, by using the above equation, we can definitely determine the rate of heat transfer through a plane -wall.

Note: for your ease, I have drawn a schematic of the plane-wall and attached in the attachment.

Answer:

1. A ball rolls down a ramp for 15 seconds. If the initial velocity of the ball was 0.8 m/sec and the final velocity was 7 m/sec, what was the acceleration of the ball?. Mrs. Bontkowski watches Connor Ladone on the basketball court. With an initial speed of 0 m/s and final speed of. 14 m/s, he accelerates at a rate of 2 m/s? If a Creature Cat's Ferrari, with an initial speed of 10 m/s, accelerates at a rate of 50 m/s/s.Mrs. Bontkowski watches Connor Ladone on the basketball court.

Explanation:

Hope this helps you!

Answer:

The first velocity is 0.19

The second velocity is 0.45

Explanation:

The position of the center of mass of the system remains constant during the experiment.

The principle of conservation of linear momentum states that the total momentum of the system before after collision is always conserved for both elastic and inelastic collision.

[tex]m_1 u_1 + m_2 u_2 = m_1 v_1 + m_2 v_2\ \ (elastic)\\\\m_1 u_1 + m_2 u_2 = v(m_1 + m_2 ) \ (inelastic)[/tex]

The total kinetic energy of the system is conserved for perfectly elastic collision BUT not conserved for inelastic collision.

The center mass of the system is always constant.

Thus, the position of the center of mass of the system remains constant during the experiment.

Learn more about elastic and inelastic collision here: https://brainly.com/question/7694106

Answer:

[tex]\displaystyle \rho=1.25\ g/ml[/tex]

Explanation:

Density

The density of a substance is the mass per unit volume. The density varies with temperature and pressure.

The formula to calculate the density of a substance of mass (m) and volume (V) is:

[tex]\displaystyle \rho=\frac{m}{V}[/tex]

The cube has a mass of m=3.75 g and a volume of V=3 ml, thus the density is:

[tex]\displaystyle \rho=\frac{3.75\ g}{3\ ml}[/tex]

[tex]\boxed{\displaystyle \rho=1.25\ g/ml}[/tex]

Since 1 kg=1000 mg and 1 lt = 1000 ml, the density has the same value but with different units:

[tex]\displaystyle \rho=1.25\ kg/l[/tex]