Question

A body of mass 2 kg is moving toward north with a speed of 4 $m{s}^{-1}$ . A force of 4 N is applied on it toward west . Displacement of the body 2 seconds after the force is applied

• A. 4$\sqrt{5}m$
• B. 4$\sqrt{2}m$
• C. 5$\sqrt{4}m$
• D. 5$\sqrt{2}m$

Answer 1

The correct option is A 4$\sqrt{5}m$

Displacement towards North will be $x_N=vt=4\times 2=8meter$

Displacement towards West will be $x_W=\frac{1}{2}a{t}^2=\frac{1}{2}\frac{4Newton}{2Kg}{2}^2=4meter$

as north and west are $perpendicular$ to each other so the net displacement will be $x=\sqrt{x_N^2+x_W^2}=4\sqrt{5}meter$