Question

At a place where the acceleration due to gravity is 10 m $se{c}^{-2}$ a force of 5 kg-wt acts on a body of mass 10 kg initially at rest. The velocity of the body after 4 second is:

• A. 5 m $se{c}^{-1}$
• B. 10 m $se{c}^{-1}$
• C. 20 m $se{c}^{-1}$
• D. 50 m $se{c}^{-1}$

Answer 1

The correct option is C 20 m $se{c}^{-1}$

Given : $g=10m/s^2$ $F=5kgwt=50N$ $M=10kg$

Initial velocity $u=0$

Acceleration $a=\frac{F}{M}=\frac{50}{10}=5m/s^2$

Velocity $v=u+at$

Or $v=0+5\times 4=20m/s$