To solve the problem it is necessary to apply energy conservation.
By definition we know that kinetic energy is equal to potential energy, therefore
PE = KE

Where,
m = mass
g = gravitaty constat
v = velocity
h = height
Re-arrange to find h,

Replacing with our values


Therefore the correct answer is C.
Answer:
A sloping surface separating air masses that differ in temperature and moisture content is called a front.
One fixed pulley doesn't change the strength of the force that
pulls on the rope. The pulley only changes its direction. So,
to lift a 50-N load, you need to pull on the rope with at least 50-N .
Explanation:
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