Question

A bullet has a momentum of 3.2 kg*m/s. What is its mass if it is traveling at 762 m/s

Answer 1

Momentum is the product of the mass of a given body and its velocity therefore a body at rest has zero momentum.
Mathematically; momentum = velocity (in m/s) × mass (in kilograms)
     therefore, reversing the formula:
mass will be given by the momentum divided by the velocity of the body
thus; 
                3.2 kg*m/s ÷ 762 m/s =0.0041995 kg
which is approximately 0.0042 kg (4 decimal places) or 4.2 grams (1000 g =
1 kg).