A body of mass $10\, kg$ is moving with a constant velocity of $10 \,m/s$. When a constant force acts for $4 \,seconds$ on it, it moves with a velocity $2 \,m/sec$ in the opposite direction. The acceleration produced in it is...........$m/{\sec ^2}$
$3$
$ - 3$
$0.3$
$ - 0.3$
A body of mass $10\, kg$ is moving with a constant velocity of $10 \,m/s$. When a constant force acts for $4 \,seconds$ on it, it moves with a velocity $2 \,m/sec$ in the opposite direction. The acceleration produced in it is...........$m/{\sec ^2}$
$v = u + at$ $ \Rightarrow - 2 = 10 + a \times 4$ $ \Rightarrow a = - 3m/se{c^2}$