Question

1. A 700kg racecar slowed from 30m/s to 15 m/s. What was its change in Momentum?

2. If the car in the above problem took 5 seconds to slow down from 30m/s to 15 m/s.
a. What is the impulse?
b. What was the average force applied by the brakes?

Answer 1

Note that impulse is just the change in momentum \[F = \frac{ m \Delta v }{ t } \implies m \Delta v = Ft \implies \Delta p = Ft\]