Question

6.4 kJ of energy causes a displacement of 64 m in a body in the direction of force in 2.5 seconds. Calculate:

1. Applied force.
2. Power in horse power [Take 1 HP = 750 W]

Answer 1

Give: Energy used, W = 6.4 kJ

= 6400 J

Displacement, s = 64 m

Time, t = 2.5 s

(a) Force applied:
W = F × s

F = `W/s`

= `6400/64`

= 100 N

(b) Power in horse power:

P = `W/t`

= `6400/2.5`

= 2560 W

Using 1 HP = 750 W:

Power in HP = `2560/750`

≈ 3.41 HP