Question

A force of 20 N acts on a body and the body moves through 1 m at an angle of ${45}^o$ to the direction of the force. The work done by the force is.

• A. $10\sqrt{2}J$
• B. $\frac{10}{\sqrt{2}}J$
• C. $-10\sqrt{2}J$
• D. $\frac{-10}{\sqrt{2}}J$

Answer 1

The correct option is A $10\sqrt{2}J$

Work done is defined as force into displacement

Work done = FCos$\theta$

= 20 $\ast$ 1 $\ast$ Cos45 (The value of Cos45 is $\frac{1}{\sqrt{2}}$)

= 20 $\ast$ $\frac{1}{\sqrt{2}}$

= 10$\sqrt{2}$ J