Calculating Velocity and Momentum in Inelastic Collisions

AI Thread Summary
The discussion focuses on calculating the velocity and distance traveled by two putties after a completely inelastic collision. The first putty, with a mass of 5, compresses a spring with a stiffness constant of 3 and a displacement of 6, allowing for potential energy conversion into kinetic energy. The potential energy of the spring is calculated using the formula PE=1/2kx^2, which is then equated to the kinetic energy of the first putty to find its velocity after leaving the spring. Conservation of momentum is applied to determine the final velocity of the combined mass of both putties post-collision. The conversation raises questions about the effects of friction on the motion, indicating a need for clarification on any external forces affecting the putties' travel.
mwahx3
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Putty of mass 5 is compresses a spring with stiffness consonant 3. The spring is stretched and the putty has a completely inelastic collision with another putty of mass 15. How fast and how far do the putties travel?

I have no idea how to begin.

thanks,,
 
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me neither...
are you sure it didn't tell you the displacement of the spring, if it gave you that the problem would be solvable
 
oh, right sorry. i forgot to include that -- 'with a distance of 6'

thanks for pointing that out.
 
oh, in that case...
PE=1/2kx^2 for spring... where k is the stiffness constant and x is the displacement
the spring transfers all its PE to the first putty's KE, so now you want to do KE=1/2mv^2 solving for the velocity of the first putty after it leaves the spring...
then do conservation of momentum... mv before= mv after
*the mass and velocity before is just the mass and velocity of the first putty, the mass after is the mass of both together and the velocity after is the joint velocity which you are solving for...
uhhh, the distance I am not so sure about
you didn't mention any friction in the problem so I assumed there was none... what exactly makes them slow down?
 

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