Average Force in a Collision

## Question:

Ft=mv-mu , where the force F is the
AVERAGE FORCE. What is the meaning of that AVERAGE? Is there any
graph to show it physical meaning?
Thanks very much for answering the questions!!!

## Answer:

Because an impulsive force is over so quickly knowing the details
of how an impulsive force varies with time is difficult. We
frequently deal with the average force. Newton's second law
may be stated in terms of changes in momentum in that the force
is the rate of change of momentum. The average force during an
impulse is that force which would produce the same change in
momentum as the actual force. If we are willing to assign the
average force to the whole time interval of the impulse, this
becomes F=(change in momentum) divided by
(change in time). Or F times the (change
in time)=(change in momentum). Which is the formula you
have in your question.
The connection between the graph of the actual impulsive force
with respect to time and that of the average force with resect to
time is that the area under both graphs is equal. The actual
impulse graph will be some sort of peak looking thing, the
average force graph will be a square wave, flat on top.

This information is brought to you by M. Casco Associates, a
company dedicated to helping humankind reach the stars through
understanding how the universe works. My name is James D. Jones.
If I can be of more help, please let me know.

JDJ