A woman in a movie fires a gun and is pushed backwards. The mass of the bullet is 0.050 kg and the bullet velocity is +850 m/s. The woman's mass ( including the gun) is 62 kg.
I) What is the recoil velocity of the woman?
II) If she shoots a blank cartridge with a mass of 0.0010 kg, what is her recoil velocity?
III) If the entire process of firing (the first bullet) occurs in a time-span of 0.025 s, then what is the average force applied by the gun on the bullet?