Question

Ahorse pulls a cart by 7.2km/hr speed while applying 40N force at an angle of 60 degree from
the horizontal for one minute. Calculate the work done by the horse and the power used by the horse.

Answer 1

v = 7.2 km / hr = 7.2 * 5/18 m/s = 2 m /s

F = 40 N

Ф = 60°

t = 1 min = 60 s

Using relation,

v = d / t

2 = d / 60

d = 120 m

Distance travelled = 120 m

Work done( W ) = f d cosФ = 40 * 120 * cos 60

                          = 4800 * 1/2 = 2400 J

Power ( P ) = W / t = 2400 / 60 = 40 W