Question

How does inertia affect a person who is not wearing a seatbelt during a collision?

Answer 1

En caso de una colisión de bajo nivel de gravedad podría golpearse con el tablero del carro o en la parte del sillón (si esta sentado en la parte trasera). Pero si es muy grave la colisión podría salirse del carro por el cristal.

Answer 2

Well an object in motion stays in motion. the body would continue to go at the speed the car was going before it was hit, and then the boy would go threw the windshield (if they are in the front seat). Which means inertia wouldn't have any affect on the person until they hit the windshield and then the pavement. Hope this makes sense to you!