Question

A man applies a force of 315 N to push the block of 225 kg onto 10 m ramp. Calculate the efficiency of the person if the mass gains a height of 1.2 m.​

Answer 1

Answer:

η = 0.84 = 84%

Explanation:

The efficiency of the man can be given by the following formula:

η = output/input

where,

η = efficiency of man = ?

output = potential energy gain of the block = mgh

input = work done by man = Fd

Therefore,

$\eta = \frac{mgh}{Fd}$

where,

m = mass of block = 225 kg

g = acceleration due to gravity = 9.81 m/s²

h = height gained by block = 1.2 m

F = force exerted by man = 315 N

d = distance covered by man = 10 m

Therefore,

$\eta = \frac{(225\ kg)(9.81\ m/s^2)(1.2\ m)}{(315\ N)(10\ m)}$

η = 0.84 = 84%