Question

Formula for power in terms of mass gravity distance and time

Answer 1

1. The problem statement, all variables and given/known data How much power does a weightlifter expend when lifting a 50kg barbell a distance of 1.2m in a time interval of 1.5s? 2. Relevant equations Power=work done/time interval (in Newton meters per second or Watts) Work=Fd (in Newton meters or Joules) 3. The attempt at a solution Power = Fd/t = (m)(a)(d)/t = 50kg(9.8 m/s2)(1.2m)/1.5s = 392 Nm/s = 392 W This is how I solved the problem, but my professor said the correct answer is 40 Watts! Work = force x distance; work = 50 kg x 1.2 m, work = 60 Power = work /time; 60/1.5 = 40 Watt t