Suppose a car's coasting towards you at 100km/hr.

You can turn it around using no force. So you can reach out your hand, grab the wing mirror, and the car will spin round and head off in the opposite direction as you let go at the right time.

F=ma. Please look up Wikipedia or a high-school general science textbook instead of saying made up things.

Originally Posted By: paul


To a physicist, 'acceleration' includes a change in speed or direction. Look up wikipedia to get a more thorough picture. This is the same acceleration in F=ma so it's crucial that we use a consistent definition.

I have a clear understanding of that , and physicist also use decelerate to describe using a force to decelerate a object.

picking at straws are we?

Edited by kallog (06/23/10 01:27 PM)