How to Calculate Distance Traveled in a Momentum Problem with Friction

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Homework Help Overview

The discussion revolves around a physics problem involving a downward curving slope, friction, and an inelastic collision between two blocks of mass. The original poster describes a scenario where one block slides down a frictionless track and collides with another block at the bottom, which is subject to kinetic friction.

Discussion Character

  • Exploratory, Conceptual clarification, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants discuss the application of the work-energy theorem to determine the velocity of the first block before the collision. There are questions about the conditions of the second block and the lack of initial velocity information. Some suggest using momentum conservation for the inelastic collision and exploring the resulting motion under friction.

Discussion Status

The discussion is ongoing, with various interpretations of the problem setup being explored. Some participants have offered potential approaches to calculate the distance traveled after the collision, while others seek clarification on the conditions affecting the blocks' motion.

Contextual Notes

There is uncertainty regarding the initial height of the first mass and the specific conditions of the second mass during the collision. The absence of initial velocity data is also noted as a constraint in solving the problem.

Spectre32
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ALright i seem to be a little stuck on a Homework problem. basically there is a downward curving slope that level so for a few meters> throuhgout a good chunk of the problem the track is frictionless. And the end the coeff of kenetic friction is .50. They want to know how far the complelty inelastic system travels. For the problem set up there is a block of mass M1 sliding down the slide. At the bottem there is another block of Mass 2.00M1. This is all the information I'm given.
 
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So, is m2 on the rough part of the track? If you know how high m1 started at, you can use the work-energy theorem to find how fast it is going on the level part of the frictionless track before it hits m2. For the inelastic collision, you know that momentum is conserved and that the two masses get stuck together, effectively becoming a single object with mass = m1+m2 (this means the new velocity is m1*vi/(m1+m2)). After that, you have a constant acceleration problem with a known initial velocity, which you can use to find the total distance traveled (I'm thinking along the lines of vf^2 - vo^2 = 2*a*x, where a<0 (constant deceleration from the kinetic friction), vf = 0, and vo is found from the momentum conservation above.
 
Well m2 isn;t on the friction surface there both on the non friction part of the track and then they slide on to the friction part. Also no velocity is givin.
 
Well, the blocks will slide together at a constant velocity until they hit the friction section, so if you call that distance D and the distance they travel with friction h, the total distance traveled together is D+h. You can solve for h in terms of H, the initial height of the first mass (I did it quickly and got h = 2H/9, but you should work it out to see what you get). That's the best I can think of; maybe someone else on the forum can help more if that's not what your teacher's looking for.
 

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