Question

A man spends 6.4 kJ energy in displacing a body by
64 m in the direction in which he applies force, in
2.5 s. Calculate :
(i) the force applied, and
(ii) the power spent (in H.P.) by the man.
​

Answer 1

Explanation:

power =E/T

power =6400/2.5

power=2560

force ?

Answer 2

Answer:

100 N

3.43 H.P

Explanation:

Energy = 6.4 kJ

Energy = 6400 J

Displacement = 64 m

Time = 2.5 sec

Work = Force × Displacement

Force = Work ÷ Displacement

Force = 6400 ÷ 64

Force = 100 N

Power = Work done ÷ Time taken

Power = 6400 ÷ 2.5

Power = 6400/25 × 1/10

Power = 2560 W

1 H.P = 746 W

? H.P = 2560 W

? H.P = 2560 ÷ 746

? H.P = 3.43 H.P

∴,

1. The force applied is 100 N.

2. The power spent by the man in H.P is 3.43 H.P.