Below is a copy of the problem and questions that are asked. I'm pretty sure that this has to be a conservation of energy problem, but I keep getting the wrong answer for the first problem so I can't continue and try the others.(adsbygoogle = window.adsbygoogle || []).push({});

I set the KE of the moving block equal to the PE of the spring that it strikes to determine X meters. I get 0.41m....which is wrong. Any help is greatly appreciated.

A 3.0 kg block slides along a frictionless tabletop at 7.0 m/s toward a second block (at rest) of mass 6.0 kg. A coil spring, which obeys Hooke's law and has spring constant k = 860 N/m, is attached to the second block in such a way that it will be compressed when struck by the moving block, Fig. 9-40.

What will be the maximum compression of the spring?

m

(b) What will be the final velocities of the blocks after the collision? (Assume the initial direction of the 3.0 kg block is positive.)

3.0 kg block

m/s

6.0 kg block

m/s

(c) Is the collision elastic? (Compare energy values to the nearest joule.)

yes***

no

Give the kinetic energy of the system before and after the collision to justify your answer.

before

J

after

J

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# Homework Help: Block hits block with spring. Conserv of Energy and Momentum?

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