Motion, Momentum and Transportation Safety

Speed, distance and time, momentum, and the impulse ideas behind seat belts, airbags and crumple zones.

12 questions, free, marked as you go with a worked explanation on every one.

What this covers

A truck travels 240 km in 3 hours at a steady speed. What is its average speed, in kilometres per hour?
A car travels at a steady 25 m/s for 12 seconds. Using d = vt, how far does it travel, in metres?
A car of mass 1 200 kg travels at 25 m/s. Using p = mv, what is its momentum, in kilogram metres per second?
A 70 kg passenger is brought from 15 m/s to rest in 0.25 s by a seat belt. Using F = mΔv / Δt, what average force does the belt apply, in newtons?
That same 70 kg passenger is brought from 15 m/s to rest, but an airbag stretches the stopping time from 0.25 s to 0.75 s. What average force acts on them now, in newtons?
Why is a car with a crumple zone safer than one built to be completely rigid?
A 1 500 kg car travelling at 20 m/s runs into a stationary 1 000 kg car and the two lock together. What is their common speed immediately afterwards, in metres per second?
A driver travelling at 25 m/s takes 1.5 s to react before touching the brakes. Using d = vt, how many metres does the vehicle travel during that reaction time alone?
A bicycle and rider have a combined mass of 80 kg and travel at 6 m/s. Using p = mv, what is their momentum?
A 0.5 kg ball is thrown at 20 m/s. Using p = mv, what is its momentum?
Two objects have the same momentum. Object A has twice the mass of Object B. How do their speeds compare?
A 1500 kg car decelerates from 20 m/s to rest. What is the magnitude of the change in its momentum?