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).
