Question

A man raises a box of mass $50kg$ to a height of $2m$ in $2minutes$, while another man raises the same box to the same height in $5minutes$. What is the ratio of work done by them ?

• A. $2:1$
• B. $1:2$
• C. $1:1$
• D. $4:1$

Answer 1

Answer: (C)

$Work=Fs\cos \theta$

where, $F$ is the force applied, $s$ is the displacement, and $\theta$ is the angle between the force applied and displacement

Hence, work done is independent of time taken.

In the given cases, $\theta =0^{\circ }$ as the force applied are in the same direction. Also, $F=mg$

So $W=Fs=mgs$

In both the cases, mass and displacement are the same.
$W=50\times 10\times 2=1000J$