Question

The acceleration of Particle starting from rest and moving along a straight line is as shown. Other than at $t=0$, when is the velocity of the object equal to zero?

• A. At $t=3.5s$
• B. During the interval from $1s$ to $3s$
• C. At $t=5s$
• D. At no other time on this graph

Answer 1

Answer: (D)

At no other time on this graph

area of $a-t$ graph given change in velocity at origin $v_i=0$

$v_f-v_i=area$

$v_f=area$

$Area=A_1+A_2$

$A=\frac{1}{2}\times 5\times (3.5+2)-\frac{1}{2}\times 5\times 1.5$

$A=\frac{1}{2}\times 5(3.5+2-1.5)=10$

Area is not zero,

so at no point velocity will be zero