A coil of wire of cross-section 0.75 square mm weighs 125g in air and 115g in water. What will be the length of the coil?
A block of metal weighing 2kg is resting on a frictionless plane. It is struck by a jet releasing water at the rate of 1kg/s and at a speed of 5m/s. Find the initial acceleration of the block.
During a football match, the ball shot towards the goal struck the defender's foot at the speed of 10m/s and it bounced back at 20m/s. If the time of impact was 0.2 sec, and mass of the ball 0.5 kg,then find the average force exerted by defender on the ball.
In a rocket, fuel burns at the rate of 1kg/s. This fuel is Ejected from the rocket with a velocity of 60km/s. What force will be exerted on the rocket?