Question

A force of $2\text{N}$ acts on a body of $20\text{kg}$. As, a result, the body covers $100\text{cm}$ in $4\text{s}$, moving along a straight line. Find the initial velocity.

• A. $0\text{cm/s}$
• B. $7\text{cm/s}$
• C. $5\text{cm/s}$
• D. $8\text{cm/s}$

Answer 1

The correct option is C $5\text{cm/s}$

Acceleration of the body, $a=\frac{F}{m}=\frac{2}{20}=0.1{\text{m/s}}^2=10{\text{cm/s}}^2$

Now,

$s=ut+\frac{1}{2}a{t}^2$

$\Rightarrow 100=4u+\frac{1}{2}\left(10\right)(4{)}^2$

$\Rightarrow u=5\text{cm/s}$