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 ▸how do i convert from a sine angle to a cosine angle?
A cylindrical specimen of material with diameter 1.5x10^-4 has a breaking stress of 1.3GPa. Calculate the tensile force acting on the specimen at breaking point.
A simple pendulum is an example of a system in Simple Harmonic Motion, using conservation laws find a) the greatest speed of the bob and b) the magnitude of speed at a height of 1.0cm above the minimum point. Given it starts at rest, at a height of 20cm.
Describe and explain the first stages of the life cycle of a star before it reaches the main sequence.