Question

A particle, after starting from rest experiences constant acceleration for $20\text{seconds}$. If it covers a distance of $S_1$ in first $10\text{seconds}$ and distance $S_2$ in next $10\text{seconds}$, then

• A. $S_2=S_1/2$
• B. $S_2=S_1$
• C. $S_2=2S_1$
• D. $S_2=3S_1$

Answer 1

The correct option is D $S_2=3S_1$

Let the constant acceleration be $a$
Given, $u=0$
For first $10\text{seconds}$
$S_1=ut+\frac{1}{2}a{t}^2$
$S_1=0+\frac{1}{2}a(10{)}^2$
$S_1=50a$ …….(1)
Total displacement in $20\text{seconds}$
$S=0+\frac{1}{2}a(20{)}^2=200a$
$\Rightarrow S_2=S–S_1=150a$.....(2)
From (1) and (2)
$\frac{S_2}{S_1}=\frac{150a}{50a}\Rightarrow S_2=3S_1$