Question

A body starts from rest and moves with uniform acceleration for 3s. It then decelerates uniformly for 2s. and stops. If the deceleration is $3{ms}^{-2}$ the maximum velocity of the body is ____ ${ms}^{-1}$

• A. zero
• B. 2
• C. 6
• D. Cannot be determined

Answer 1

The correct option is C 6

Velocity will be maximum before the deceleration starts.

Given Final Velocity v=0, acceleration $a=-3m{s}^{-2}$ and time $t=3s$,

Let maximum velocity is $u_{max}$,

Using $v=u+at$ $\Rightarrow 0=u_{max}-3\times 2$ $\Rightarrow u_{max}=6m{s}^{-1}$