Question

A particle starts to move from rest with an acceleration of 4 $\frac{m}{s^2}$ for 4 seconds. Find the distance travelled in $4^{th}$ second.

• A. 32 m
• B. 14 m
• C. 10 m
• D. 30 m

Answer 1

The correct option is B

14 m

We know, acceleration, a= 4 $\frac{m}{s^2}$ and initial velocity, u= 0

Using second equation of motion

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

The distance covered in 3 second is:

$\Rightarrow S=0\times 3+\frac{1}{2}\times 4\times 3^2$

$\Rightarrow S=2\times 3^2$

$\Rightarrow S=18m$

The distance covered in 4 seconds is:

$\Rightarrow S=0\times 4+\frac{1}{2}\times 4\times 4^2$

$\Rightarrow S=2\times 4^2$

$\Rightarrow S=32m$

Distance covered in $4^{th}$ second

= Distance covered in 4 seconds - Distance covered in 3 seconds

=32 m - 18 m

=14 m