Question

A body of mass $10 \,kg$ is moving with a constant velocity of $10 \,m/s$. When a constant force acts for $4 s$ on it, it moves with a velocity $2 \,m/s$ in the opposite direction. The acceleration produced in it is

• A. $3 \,m/s^2$
• B. $- 3\, m/s^2$
• C. $0.3\, m/s^2$
• D. $- 0.3 \,m/s^2$

Answer 1

Answer: (B)

$- 3\, m/s^2$

Answer 2

Given, $m=10 \,kg,$ $u=10\,m/s,$ $t=4\,s$ $v=-2\,m/s$ By $v=u+at$ $-2=10+a\times 4$ $\Rightarrow$ $a=-3\,m/s^{2}$