When light above the threshold frequency of a metal is shone on the metal, photoelectrons are emitted. If the power of the light halves, are the maximum kinetic energy of the photoelectrons and/or the number of photoelectrons altered, and if so, how?
When the power of the light is halved, there are half as many photons per unit time. Therefore, the number of photoelectrons emitted is also halved. The maximum kinetic energy of the photoelectrons depends on the frequency of the light, so the maximum kinetic energy of the photoelectrons does not change, because the frequency of the light has not changed.
SS
Related Physics A Level answers
All answers ▸A body is moving at 70km/h and has a mass of 130kg, calculate its maximum kinetic energy.
Hydrogen has a single proton and a single electron. Find the electric potential at a distance of 0.50 * 10^(-10) (m) from the proton.
A motorist traveling at 10m/s, was able to bring his car to rest in a distance of 10m. If he had been traveling at 30m/s, in what distance could he bring his cart to rest using the same breaking force?
You are sitting in a boat on a lake, you have with you in the boat a large rock. You throw the rock out of the boat and it sinks to the bottom of the lake, does the water level of the lake go up, down or stay the same?