Question

A force of $100N$ acting on a body for $5$ second gives it a velocity of $20m{s}^{-1}$. Calculate the mass of the body.

• A. 50 kg
• B. 25 kg
• C. 75 kg
• D. 100 kg

Answer 1

The correct option is(B) 25 kg

We know,

Initial velocity of the body is zero

Acceleration can be found using first equation of motion $v=u+at$

So,

$\Rightarrow 20=0+5a$

$\Rightarrow a=4m/s^2$

Now we know,

Acceleration of body $=\frac{F}{m}=\frac{100}{m}=4m/s^2$

where, $m$ is mass

$\Rightarrow m=25kg$

Hence, the mass of the body is 25 kg