Questions from Modern Physics

Q: An x-ray tube is operating at voltage V and current

An x-ray tube is operating at voltage V and current I. a. If only a fraction p of the electric power supplied is converted into x rays, at what rate is energy being delivered to the target? b. If th...

Q: A photon with wavelength 0.1100 nm collides with a free

A photon with wavelength 0.1100 nm collides with a free electron that is initially at rest. After the collision the wavelength is 0.1132 nm. a. What is the kinetic energy of the electron after the co...

Q: An x-ray photon is scattered from a free electron (

An x-ray photon is scattered from a free electron (mass m) at rest. The wavelength of the scattered photon is λ′, and the final speed of the struck electron is v. a. What was the initial wavelength λ...

Q: In developing night-vision equipment, you need to measure the

In developing night-vision equipment, you need to measure the work function for a metal surface, so you perform a photoelectric-effect experiment. You measure the stopping potential V0 as a function o...

Q: When a converging lens is immersed in water, does its focal

When a converging lens is immersed in water, does its focal length increase or decrease in comparison with the value in air? Explain.

Q: While analyzing smoke detector designs that rely on the photoelectric effect,

While analyzing smoke detector designs that rely on the photoelectric effect, you are evaluating surfaces made from each of the materials listed in Table 38.1. One particular application uses ultravio...

Q: To test the photon concept, you perform a Compton-scattering

To test the photon concept, you perform a Compton-scattering experiment in a research lab. Using photons of very short wavelength, you measure the wavelength λ′ of scatt...

Q: a. If the average frequency emitted by a 120-W

a. If the average frequency emitted by a 120-W light bulb is 5.00 * 1014 Hz and 10.0% of the input power is emitted as visible light, approximately how many visible-light photons are emitted per secon...

Q: The emission of a photon by an isolated atom is a recoil

The emission of a photon by an isolated atom is a recoil process in which momentum is conserved. Thus Eq. (39.5) should include a recoil kinetic energy Kr for the atom. Why is this energy negligible i...

Q: As a body is heated to a very high temperature and becomes

As a body is heated to a very high temperature and becomes self-luminous, the apparent color of the emitted radiation shifts from red to yellow and finally to blue as the temperature increases. Why do...