As wavelength increase, the frequency of the wave increases / decreases.

In which one of the following situations is zero net work done? A) A ball rolls down an inclined plane. B) A physics student str

lidiya [134]

Answer:

Option D

Explanation:

The work done can be given by the mechanical energy used to do work, i.e., Kinetic energy and potential energy provided to do the work.

In all the cases, except option D, the energy provided to do the useful work is not zero and hence work done is not zero.

In option D, the box is being pulled with constant velocity, making the acceleration zero and thus Kinetic energy of the system is zero. Hence work done in this case is zero.

6 0

4 years ago

Read 2 more answers

How are reversibility, time, and entropy connected

kondor19780726 [428]

Answer:

As one goes "forward" in time, the second law of thermodynamics says, the entropy of an isolated system can increase, but not decrease. ... Thus, entropy measurement is a way of distinguishing the past from the future.

Explanation:

6 0

3 years ago

The latent heat of vaporization for ethyl alcohol is 854 J/g. The amount of energy, rounded to the nearest whole number, needed

Lorico [155]

Answer:

4441 J

Explanation:

The amount of energy needed to change the ethyl alcohol from liquid to gas state is given by

$Q=m \lambda_v$

where

m = 5.20 g is the mass of the alcohol

$\lambda_v = 854 J/g$ is the latent heat of vaporization of the substance

Substituting the numbers into the formula, we find:

$Q=(5.20 g)(854 J/g)=4,441 J$

7 0

4 years ago

What is the thinnest film (but not zero) of MgF2 (n = 1.38) on glass that produces a strong reflection for orange light with a w

Art [367]

The concept required to solve this problem is related to thin film interference.

The path length difference between two waves one is reflected from top surface of the film and the bottom surface of the film is equal to twice the thickness of the film:

$\gamma = 2t$

Where,

$\gamma =$ Path length difference

t = thickness

At the same time we have that the constructive interference condition for a thin film interference for strongly reflected rays is

$\gamma = m\lambda$

Where

$\gamma =$ Path length difference

$\lambda =$ wavelength

m = Any integer (order of the equation) which represent the number of repetition of the spectrum

Equation both expression we have

$2t = m\lambda$

Re-arrange to find the thickness we have

$t = m\frac{\lambda}{2n}$

Our values are given as

m = 1

$\lambda$ = 597nm

n = 1.38

Replacing,

$t = (1)\frac{597}{2(1.38)}$

$t = 216.3nm$

Therefore the thinnest thickness of the film is 216.3nm

6 0

3 years ago

how much power is radiated as a sound from a band whose intensity is 1.6x10-3 w/m2 at a distance of 12m

Vesna [10]

2.89watts.

<h3>What is meant by sound intensity?</h3>

The average rate at which sound energy moves across a unit area normal to a given direction is used to determine a sound's intensity. This rate is generally stated in ergs per second per square centimeter.
Decibels are the units used to measure sound intensity, often known as sound power or sound pressure. The decibel (dB) unit is named after Alexander Graham Bell, who also created the audiometer and the telephone. An audiometer is a tool to gauge a person's hearing capacity for various noises.
Our ability to measure the flow of sound energy as a time-averaged vector quantity makes sound intensity measuring an effective method. We can identify sound sources and tell direct sound from reverberant sound in a room using the characteristics of sound intensity.

How much power is radiated as a sound from a band whose intensity is 1.6x10-3 w/m2 at a distance of 12m:

Formula: $I\frac{P}{4\pi r^{2} }$