A hunter on a frozen, essentially frictionless pond uses a rifle that shoots 4.20-g bullets at 965 m/s. The mass of the hunter (including his gun) is 72.5 kg, and the hunter holds tight to the gun after firing it. Find the recoil velocity of the hunter if he fires the rifle (a) horizontally and (b) at 56.0° above the horizontal.
Solution 25E Introduction We will use the concept of conservation of momentum to calculate the velocity of the hunter. Step 1 The momentum of the bullet is Mass of the bullet isbm = 4.20 g = 0.042 kg and the velocity of the bulleb is v = 965 m/s. Hence the momentum of the bullet is Now to keep the momentum conserved, the momentum of the hunter should also be same in magnitude and opposite in direction. The mass of the hunter hs m = 72.5 kg. Now ih v is the velocity of the hunter then we have Hence the velocity of the hunter will be 0.559 m/s if the bullet was fired horizontally.