Numerical Problems based on Newton’s Laws

1.A machine gun has a mass of 20 kg. it fires 30g bullets at the rate of 400 bullets per second with a speed of 400 m/s. what force must be applied to the gun to keep it in position?
2.A ball of mass 20g hits a wall at an angle of 45 degree with a velocity of 15 m/s. if the ball rebounds at 90 degree to the direction of incidents, calculate the impulse received by the ball.