A 900-kg car is traveling at 15 m/s. The driver of the car brakes and the speed is reduced to 5 m/s. What is the car's change in momentum?

Question

Quizplus · Accepted Answer

The equation for momentum is p = mv. Since the mass of an object remains the same, only its velocity is changed. Thus, the formula for change in momentum is written as Δp = mΔv. The symbol Δ is called "delta" and is used to represent a change in the magnitude (number). In this case, we are using it to represent the change in velocity. Δp = mΔv Δp = (900 kg) (v₂ - v₁) Δp = (900 kg) (5 m/s - 15 m/s) Δp = (900 kg)(-10 m/s) Δp = - 9000 kg m/s Since the car was slowed down, the change in momentum is negative, which reflects a decrease in the momentum.

A 900-Kg Car Is Traveling at 15 M/s