Question

A mass of 100 kg is being pushed along the floor at a constant velocity of 2 m/s. If the coefficient of kinetic friction is 0.25, at what rate is work (power) being done in watts, in horsepower?

Answer 1

Gives

Mass(m)=100kg

$\mu=0.25$

Velocity (v)=2$m/sec$

$F=\mu R=\mu mg$

F=$0.25\times100\times 9.8=245N$

Power

$P=F.v$

$\frac{dW}{dt}=P=245\times2\cos0°$

$\frac{dW}{dt}=P=490W$

$\frac{dW}{dt}=P=\frac{490}{746} hp=0.6568hp$

1 hp=746W

$P=\frac{dW}{dt}=0.6568hp$