The answer is c. the force of his swing
At the time of the impact, there is a collision between two bodies moving in opposite directions.
The force exerted on the ball causes the change of velocity.
Is that a question? .
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A wave looses its power as it comes to shore because it gets less deeper every second it gets closer to shore
Answer: 430 nm.
Explanation:
The relation of wavelength and frequency is:
Formula used :
where,
= frequency =
= wavelength = ?
c = speed of light = 
Now put all the given values in this formula, we get

Thus the wavelength (in nm) of the blue light emitted by a mercury lamp is 430 nm.