5. A ball of mass 1 kg dropped from 9.8 m height, strickes the ground and rebounds to a height of 4.9 m. If the time of contact between ball and ground is 0.1 s, then find impulse and average force acting on ball.
6. A machine gun fires a buillet of mass 50 gm with velocity 1000 m/s. If average force acting on gun is 200 N then find out the maximum number of bullets fired per minute.