Question

A particle experience a constant acceleration for 20 sec. after starting from rest, it travels adistance s${}_1$ in first 10 sec and a distance s${}_2$ in next 10 sec, then

• A. $s_2=s_1$
• B. $s_2=2s_1$
• C. $s_2=3s_1$
• D. $s_2=0.5s_1$

Answer 1

The correct option is C $s_2=3s_1$

$u=0,t=20s,a=const.$
For 1st 10 s,
$u=0,t=10$, distance travelled $=s_1$
$\therefore s_1=\frac{1}{2}.a\times {10}^2=50a,v_1=a\times 10=10a$
For next 10 s,
$s_2=10a\times 10+\frac{1}{2}.a\times {10}^2$
$=100a+50a=150a$
$\therefore s_2=3s_1$