Originally Posted By: paul

the brakes and stop the car , does it require as much force to stop the car as it did to get the car to californa from new york?

no it doesnt.


It may require more or less force. This misuse of terminology can totally lead you in the wrong direction. Of course you can gently accelerate with a tiny force and slowly get up to a high speed. Then crash into a tree with a huge force to stop. Much higher stopping force than starting force.

Equally you can floor it to accelerate with high force, then coast to a stop with a small force.

However the total impulse used to stop the car is the same as the total impulse used to start it. That's symmetric.


On the straight open road the force from the engine balances the force of friction, leaving no net force, and no acceleration - just constant velocity. So that section of the trip can be ignored.