A ball is thrown straight upward from ground with a speed of $20 \mathrm{~m} / \mathrm{s}$. The ball was caught on its way down at a point 5 m above the ground. The time taken by the ball during entire trip is (assume, $g=10 \mathrm{~m} / \mathrm{s}^2$ )

A motor-bike starts from rest, attains a velocity of 10 $\mathrm{m} / \mathrm{s}$ with an acceleration of $0.5 \mathrm{~m} / \mathrm{s}^2$, travels 10 km with this uniform velocity and then comes to halt with a uniform deceleration of $0.2 \mathrm{~m} / \mathrm{s}^2$. The total time of travel is

A body moves in a straight line with speed $v_1$ and $v_2$ for distance which are in ratio $1: 2$. Find the average speed.

Consider that a truck is moving initially with $54 \mathrm{~km} / \mathrm{h}$. It has stopped by the driver after looking at an obstacle with a deceleration of $10 \mathrm{~m} / \mathrm{s}^2$. The distance travelled by truck before coming to rest is