physics help ?
A student ( m=85 kg) runs up the stairs (h= 2.8 m) in 1.42 seconds.
a) Calculate the Energy change of the student.
b) Calculate the efficiency of the student if it took 9339 J of chemical potential energy for the student to run up the stairs
c) Calculate the output power of the student in horsepower ( 1 h.p=746 W)
- billrussell42Lv 71 month ago
work = mgh = 85•9.8•2.8 J
efficiency in perceht = 100(85•9.8•2.8/9339) =____%
power = work/time = 85•9.8•2.8/1.42 = ___ watts
or 85•9.8•2.8/1.42 watts x 1 HP/746 w = ___ HP