Calculating Acceleration in a Combined Mass System

[Stuman]

Hi, I am working on a problem that involves the following
I have a mass of 500 grams traveling at 7m/s that hits and sticks to another mass of 50 grams that was stationary.

What acceleration does the second ( 50 gram ) mass experience?

I have tried using a Runge-Kutta 4th order algorithm to solve some Differential Equations of motion and assuming a very high K value for the stiffness of the materials, but I think this is too complex.

How can I calculate the acceleration, preferably on a time basis, not just assuming that it took 0.1 seconds to get upto the new combined speed of approx 6.9?? m/s.

Thanks
Stuman

 

[chanvincent]

For the information you given... It is imposssible.
Period...

 

[Stuman]

OK. I don't want a numerical answer, I would like a methodology. Basically it is an impact related question where the two masses combine. How do you calculate the acceleration of the second 50 gram mass?

 

[PhanthomJay]

Problem is not solvable in the absence of other data.

 

[Stuman]

What other data would you like?

 

[chanvincent]

If you made a simple assumtion that the accelaration is constant, what you need is the
time interval of the impact...

 

[PhanthomJay]

What other data would you like?

Or the deformation during impact. Then the whole heap, assuming the impact takes place on a level frictionless surface , would move off at a constant speed of 6.9m/s forever and ever...

 

[Stuman]

As I said in my original post

not just assuming that it took 0.1 seconds to get upto the new combined speed of approx 6.9?? m/s.

I cannot use constant acceleration of impact time. I need to claculte it on a dynamic basis.

 

[PhanthomJay]

As I said in my original post



I cannot use constant acceleration of impact time. I need to claculte it on a dynamic basis.

Do you think it makes a difference whether the masses are made of soft clay or hardened steel?

 

[Stuman]

I do think it makes a difference which is why I stated in my original problem that during my RK4 analysis I assumed a high K value for the stiffness of the materials.

 

[PhanthomJay]

I do think it makes a difference which is why I stated in my original problem that during my RK4 analysis I assumed a high K value for the stiffness of the materials.

Why did you assume a high value? why not a low one? If I hadn't posted prior to reading chanvincent's response, i would have let it go at that...It is imposssible.
Period...

 

[Stuman]

OK, getting nowhere quick, subject is now closed.