How much work is done when a stone of mass 2 kg falls down a 10 metre high cliff?

Question

I'm stuck on this question, where do I find the force, AS Physics, thanks.

Answer 1

Since the stone is falling, the force that is accelerating it is just gravity.

F = m*g
F = (2 kg)*(9.81 m/s^2)
F = 19.62 N

The work is just
W = F x d
W = F*d*cos(angle)
W = (19.62 N)*(10 m)*cos(0)
W = 196.2 N-m

Answer 2

Hmm....

well, force equals mass times acceleration.

And acceleration is equal to g - 9.8 m/s^2...

so force would be....