Posted by **Kayla** on Wednesday, October 7, 2009 at 2:18pm.

If a 20 kg object fell to the surgace of the Earth from a height of 30m, what would its final velocity be? (work from the energy standpoint)

I know that you said it is F * X and I'm just confused. Can you help me walk through this?

- Physics -
**bobpursley**, Wednesday, October 7, 2009 at 2:24pm
Work is defined as force * distance. The force here is weight, or mg. Work done by gravity is then mgh.

Now, that work results in kinetic energy, 1/2 mv^2

1/2 m v^2=mgh

1/2 v^2=gh

v= sqrt 2gh

## Answer This Question

## Related Questions

- Physics - If a 20 kg object fell to the surgace of the Earth from a height of ...
- Physics - If a 20 kg object fell to the surgace of the Earth froma height of 30 ...
- Physics - An object of mass .550kg is lifted from the floor to a height of 3.5m ...
- physics - A 80 kg object slides at a 20 degree plane downward at 5m/s. An object...
- Science ( physics ) - A balloon is rising with a velocity of 4.9 m/sec releases ...
- physics - a boy who is 1.5m tall throws a ball into the air the ball attains a ...
- Physics - An object is observed for a 5 second interval. During this time, the ...
- college physics - An object thrown vertically upward with initial velocity from ...
- Physics - If a 1-kg mass fell toward Earth from a large distance where it had ...
- ! P H Y S I C S ! - A 5 kg mass is thrown down with a velocity of 10 m/s from a ...

More Related Questions