Question

A lawn roller is pulled along a horizontal surface through a distance of $20m$ by a rope with a force of $200N$. If the rope makes an angle of ${60}^o$ with the vertical while pulling, the amount of work done by the pulling force is:

• A. $3464J$
• B. $1000J$
• C. $2000\sqrt{3}J$
• D. $2000J$

Answer 1

Answer: (A)

$3464J$

Distance covered by the lawn roller $S=20m$

As the rope along which force is applied is making an angle ${60}^0$

with the vertical, this means it will make an angle or ${30}^0$ with the horizontal direction.

Component of force in the direction of displacement $=200\times \cos {30}^0=100\sqrt{3}$

Work done $=F\cos {30}^0\times S=100\sqrt{3}\times 20=3464J$

Hence,

option $\left(A\right)$ is correct answer.