In the united states, car accidents are the leading cause of death for teenagers. wearing seat belts save lives. describe how newton’s three laws of motion are used in testing the safety of our automobiles.

-An object in motion or at rest will stay at rest or in motion unless acted by anther force. - A seat belt keeps you from flying from your car when it is hit to help keep you still and in your seat along with an air bag.
-Force = Mass X Acceleration - Used to find how much force a human can take if the car is going at a certain speed to adjust the airbag to keep the person alive.
-For every action, there is an equal and opposite reaction - This is used to show that the car must be balanced and tested in many other ways. The car's tires and axle must be strong enough to hold the weight of the car which is right over it.

Efficiency is an action of doing something. for example when you take a test. good efficiency means you did well but bad effeciency or no effiency means you did bad.