The energy carried by the incident light is

where h is the Planck constant and f is the frequency of the light. The threshold frequency is the frequency that corresponds to the minimum energy needed to eject the electrons from the metal, so if we substitute the threshold frequency in the formula, we get the minimum energy the light must have to eject the electrons:
Metamorphic rock is not formed from A. erosion
Answer:
265 J
Explanation:
where KE is kinetic energy, PE is potential energy, m is the mass of an object, v is the speed, h is the height and g is acceleration due to gravity.
Substituting 19.7 Kg for mass, 0.934 for h, 2.93 for v and 9.81 for g then
