a. State two quantities that are conserved in an elastic collision.
b. A machine gun fires bullets of mass 0.014 kg at a speed of 640 m s⁻¹.
i. Calculate the momentum of each bullet as it leaves the gun.
ii. Explain why a soldier holding the machine gun experiences a force when the gun is firing.
iii. The maximum steady horizontal force that a soldier can exert on the gun is 140 N. Calculate the maximum number of bullets that the gun can fire in one second.