# P=w/t Power question

1. Feb 6, 2010

### dois

1. The problem statement, all variables and given/known data
How powerful is a student who can lift 60kg from the floor to above their head (2.5 meters from the ground) in 4 seconds?

2. Relevant equations
To find power we would use the equation
P= W/T

3. The attempt at a solution
I'm not sure if we would use the P=w/t equation, and work is an unknown variable, and when I try to find W, W=FxD, Force is also an unknown variable

2. Feb 6, 2010

### downwithsocks

Re: Power

What is the force on the object due to gravity (this would also be the force required to lift it)?

3. Feb 6, 2010

### dois

Re: Power

Would the force on the object due to gravity be 9.8N
so the Force required to lift it is 9.8 N

4. Feb 6, 2010

### downwithsocks

Re: Power

Force due to gravity is mg. Then use that and the distance to find the work, and the work and the time to find the power.

Last edited: Feb 6, 2010
5. Feb 7, 2010

### inutard

Re: Power

Keep in mind that the force by gravity is not 9.8 N but rather m(9.8 m/s^2) where 9.8 = g. This would be different if we were on a planet other than our homely earth.