There is a threshold frequency for each metal, and only light of a frequency higher than this threshold causes electrons to be emitted from the metal surface.
Answer:
Explanation:
For an electromagnetic wave, the relationship between magnetic field amplitude and electric field amplitude is given by
where
E is the amplitude of the electric field
c is the speed of light
B is the amplitude of the magnetic field
For the electromagnetic wave in this problem, we have
E = 10 V/m is the amplitude of the electric field
So if we solve the formula for B, we find the amplitude of the magnetic field:
golekeeper
Explanation:
because they use hand to save keeper
In empty space probably means, there is no force on the ball.
(This assumption is not quite correct since there is still the force of gravity between the ball and the astronaut, but this force is very very small and can be neglected.)
Assuming there is no force on the ball, Newtown's 1st law says: When viewed in an internal frame of reference, an object either remains at rest or continues to move at a constant velocity, unless acted upon by a force.
This means:
If there is no force on the ball, there will be no acceleration on the ball either.
If the acceleration is zero, the velocity of the ball never changes.
