Question

Suraj can open a $2m$ wide door by applying a force of $2.5N$ at the free end of the door. Find the moment of force needed to open the door.

• A. $2.5Nm$
• B. $5Nm$
• C. $7.5Nm$
• D. $10Nm$

Answer 1

The correct option is B

$5Nm$

Given, force applied at the free end,$F=2.5N$
distance between fixed and free end, $d=2m$

$\therefore \text{Moment of force}=\text{F}\times \text{d}$ $=\text{2.5 N}\times \text{2 m= 5 N m}$

Hence, the moment of force needed to open the door is $\text{5 N m}$