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:
the answer is D cuz electricity is a conductive
Answer:
the speed of the ball is 10 m/s
Explanation:
Given;
magnitude of exerted force, F = 400 N
mass of the ball, m = 2 kg
radius of the circle, r = 0.5
The speed of the ball is calculated by applying centripetal force formula;

Therefore, the speed of the ball is 10 m/s
Answer:
7,546 J
Explanation:
recall that Potential energy is given by
P.E = mgΔh
where m = 70kg (given)
g = 9.8 m/s² (acceleration due to gravity)
Δh = change in height
= distance from top of building to top of car
= height of building - height of car
= (5+8) - 2
= 11m
substituting all these into the equation:
P.E = mgΔh
= 70 x 9.8 x 11
= 7,546 J
One possible consequence is that the warmer temperature cause the polar ice to melt even faster