Momentum is mass multiplied by velocity, p = mv, and is measured in kg m/s. Momentum is a vector, so choose and retain a positive direction in calculations. At fixed mass, doubling velocity doubles momentum; this differs from kinetic energy’s speed-squared relationship. Example: An object of mass 10 kg moves east at 15 m/s. Calculate momentum, taking east as positive. p = mv = 10 × 15 = +150 kg m/s, or 150 kg m/s east. Use clear labels. State assumptions. Relate the result to the physical model.