# Impact force from a falling object

iccdan
I used some formulas to determine the impact force of a bubble wrapped 1kg object dropped 1 meter and traveling .03m after impact. But I need some help with the next part. What if an identical bubble wrapped 1kg object is placed on top and both are dropped at the same time? Will the wrapping between the two objects cause the top object to feel the same impact force? Will the bottom object feel more impact force or does the wrapping between them eliminate any influence from the top object? Thanks!

Gold Member
Hi
Which formulas?

iccdan
Sophie,
I appreciate the quick response. I used these formulas: velocity(m/s) = √2gh, kinetic energy(joules) = 1/2(mv²), impact force(Newtons) = joules/distance traveled after impact, equivalent G-force = Newtons/(kg*gravity). I also cheated and used the calculator at this Georgia State U website: http://hyperphysics.phy-astr.gsu.edu/hbase/flobi.html

Thanks

Gold Member
I think you have chosen a very difficult problem to solve here. You may be better to consider the case of two masses connected by springs, with a second spring between the first mass and the wall. Then the second mass would only be experiencing forces from the first mass during the impact. That would boil down to a fairly straightforward 'waves on a short transmission line' problem.

iccdan
Ok, now you are way over my head. Where can I get info to learn about 'waves on a short transmission line'?

Gold Member
Sorry. But you could appreciate that two masses and two springs could be a simpler problem than your original one.
It's a matter of writing an equation to describe the situation and then solving it. Easy if you say it quickly! Haha
It's the basics of all wave transmission theory.