Question

A motor delivers 8 hp to an water pump at 400 rev/min. (a) how much torque does the motor provide?
(b) how much work does the motor do in one revolution?

Answer 1

P=8 (hp)=5884 (W)

n=400 (rev/min)=6.67 (rev/s)

$M=rF=\frac{vF}{\omega}=\frac{P}{\omega}=\frac{P}{2\pi n}=\frac{5884}{6.28\cdot 6.67}=140.5$ N⋅m.

$A=Pt=\frac Pn=\frac {5884}{6.67}=882.6$ J.