# Newons laws on calculating force upon impact.

1. Nov 20, 2008

### hed54

I am currently trying to work out if two objects,
of given mass X and Y, (given in KG)
are both travelling toward eachother at Zmps,
and collide head on, and come to a complete rest.
how do i find the force of each object on impact. Without taking into account air resisitance.
I'm aware of the formula
F=ma
does this then mean simply

X*Z= A newtons
Y*Z= B Newtons
A+B= combined force of two vehicles

If so, Given that the two objects are Cars & have a crumple zone of 1.3m how will this affect my calculation.

Also, how do i calculate change in momentum, and change in enery of each vehicle?
any help appreciated as i am baffled.

2. Nov 20, 2008

### Staff: Mentor

By conservation of momentum this will only happen if X=Y. Do you want them to come to a complete rest, or do you want them to have different masses?

3. Nov 20, 2008

### Redbelly98

Staff Emeritus
The impact will take some small amount of time to happen, it doesn't occur instantaneously. The force will depend on how long this takes.

f = Δp / Δt

4. Dec 1, 2008

### hed54

forgive my earlier mistake, they do not come to a complete stop, they do have different masses. And i though that impact is an instant not a event over a period of time.

5. Dec 1, 2008

### Staff: Mentor

In the case of an instantaneous impact the force is infinite.