Two men P and Q start with velocity u at the same time from the junction of two roads inclined at `45^(@)` to each other. If they travel by different roads, find the rate at which they are being separated.

If a velocity of a train which starts from rest is 72km/h (20m/s) after 5 minute, find out its acceleration and the distance travelled by the train in this time.

A car and a truck have the same kinetic energies at a certain instant while they are moving along two parallel roads . (Assume that the truck is heavier than the car). If the mass of the truck is 100 times greater than that of the car ,find the ratio between their velocities.

Two bodies start moving in the same straight line at the same instant of time from the same origin.The first body moves with a constant velocity of 40 m/s and the second starts from rest with a constant acceleration of 4m/s^2 . a)What is uniform speed? b)Find the time that elapses before the second catches the first body.