Verified answer

Hello,

Work is force times distance moved

W = 600 N * 20 m

W = 12000 N*m (J)

That is how much energy it takes , but power is the rate at which the energy was used up. If he used 12000 J in 10 seconds, that works out to 1200 Joules each second. That is a Watt, a Joule per second.

P = W/t = 12000 J/10 sec

P = 1200 Watt

Good Luck

EDIT -- Bobs answer does not agree because of useless round -off error. He says m = F/g and calculates mass, then shoves this number into another equation which multiplies it right back times the gravity again.

If you are learning PE and not Work, do the question like this.

m = F/g ? well, instead of crunching out a number and losing precision, just shove this equation into the PE equation.

PE = mgh = (F/g)gh = F * h........Hey that's the same as Work = Force times distance, lol

P = 1200 W

mass_of_person = F / g = 600 N / 9.8 m/s² = 61.224 kg

The potential energy of the person at the top of the stairs

= mgh = (61.224 kg)(9.8 m/s²)(20 m) = 11999.904 J

Power = 11999.904 J / 10 seconds = 1199.990 Watts