Originally Posted By: paul
I have a clear understanding of that , and physicist also use decelerate to describe using a force to decelerate a object.

which object is being decelerated then kallog?

just tell me which object you think is being decelerated and what causes it to decelerate.

ie..where does the force come from that decelerates the object?

at what velocity does the object have the entire time it is decelerating.

what is the objects final velocity when it has finished decelerating?

if you are speaking about the mass as the object that is being decelerated.

1) how can a object declerate without changing its velocity.
2) there is no 2

the change in momentum you are talking about is nothing but
a change in the direction of the object.

that change in direction does not have anything to do with
the momentum of the pipe.

the force that the object presents to the pipe as it presses against the pipe while turning around is the only force that the object can possibly apply to the pipe while turning around.

and it will present a force that is exactly its
mass * its velocity.

How Force is related to Momentum

Momentum measures the 'motion content' of an object, and is based on the product of an object's mass and velocity. Momentum doubles, for example, when velocity doubles. Similarly, if two objects are moving with the same velocity, one with twice the mass of the other also has twice the momentum.

Force, on the other hand, is the push or pull that is applied to an object to CHANGE its momentum. Newton's second law of motion defines force as the product of mass times ACCELERATION (vs. velocity). Since acceleration is the change in velocity divided by time, you can connect the two concepts with the following relationship:

force = mass x (velocity / time) = (mass x velocity) / time = momentum / time

Multiplying both sides of this equation by time:

force x time = momentum

3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.