Question

The velocity of a body at any instant is 10 m/s. After 5 sec, velocity of the particle is 20 m/s. The velocity at 3 seconds before is

(assume uniform accelaration)

• A. 8 m/sec
• B. 4 m/sec
• C. 6 m/sec
• D. 7 m/sec

Answer 1

The correct option is B 4 m/sec

$v_i=10m/s$ and $v_f=20m/s$
Acceleration of the body $=\frac{20-10}{5}m/s^2$
$a=2m/s^2$
Velocity of the body at $t=-3sec$
$v=u+at$
$v=10-2\times 3$
$v=4m/s$