A car traveling about 50km/h collides head-on with something solid. The car crumples, slows down and stops. Use the law of inertia to explain why a crash dummy not restrained by a seat belt in the car slams into the steering wheel.

Answer 1

What's the Law of Inertia say? That an object in motion tends to stay in motion until acted upon by an outside forcew.
The car is traveling at 50 km/hr so the dummy, the car seats, the belts, the steering wheel and everything in the car is also traveling at 50 km/hr. When the car crashes into an at rest object it stops but the dummy is still moving. It moves into the steering wheel. Any passenger in the other seat slams into the dashboard or is sent head first through the windshield.