Question

A particle starts from rest at $t=0$ and moves in a straight line with an acceleration as shown in figure. The velocity of the particle at $t=3\text{ }s$ is

• A. $2\,m{{s}^{-1}}$
• B. $4\,m{{s}^{-1}}$
• C. $6\,m{{s}^{-1}}$
• D. $8\,m{{s}^{-1}}$

Answer 1

Answer: (B)

$4\,m{{s}^{-1}}$

Answer 2

Velocity at $3s=$ total algebraic sum of area under the curve or
$v=4\times 2-4\times 1$ $=8-4=4m{{s}^{-1}}$