Question

A particle experiences constant acceleration for $20$ seconds after starting from rest. If it travels a distance $s_1$ in the first $10$ seconds and distance $s_2$ in the next $10$ seconds, then

• A. $s_2=s_1$
• B. $s_2=2s_1$
• C. $s_2=3s_1$
• D. $s_2=4s_1$

Answer 1

The correct option is C $s_2=3s_1$

Let $a$ be the constant acceleration of the particle.
Then $s=ut+\frac{1}{2}a{t}^2$ or $s_1=0+\frac{1}{2}\times a\times (10{)}^2=50a$
and $s_2=\text{(Total distance covered in}20sec\text{)-(Total distance covered in first}10sec\text{)}$
$\Rightarrow s_2=s_{20}-s_{10}=[0+\frac{1}{2}\times a\times (20{)}^2]-50a=150a$
$\therefore \frac{s_2}{s_1}=\frac{150a}{50a}=3$
or, $s_2=3s_1$