Question

A force of $1000N$ is applied on a body of mass $100kg$ moving with the velocity of $5m/s$. How much time does it require to attain a velocity of $25m/s$ ?

• A. 8 s
• B. 6 s
• C. 4 s
• D. 2 s

Answer 1

Answer: (D)

From Newtons second law of motion,
$F=ma$ where m is mass and a is acceleration.
Given, $F=1000N,m=100kg$
$\therefore$ $a=\frac{1000}{100}=10m/s^2$
From equation of motion,
we get $v=u+at$
Where v is final velocity and $u$ is initial velocity.
Given, $v=25m/s,u=5m/s$
$\therefore 25=5+10t$
$\Rightarrow t=\frac{20}{10}=2s$ ,