(adsbygoogle = window.adsbygoogle || []).push({}); You push a 2.5 kg block against a horizontal spring, compressing the spring by 18 cm. Then you release the block, and the spring sends it sliding across a tabletop. It stops 90 cm from where you released it. The spring constant is 200 N/m. What is the block-table coefficient of kinetic friction?

Having trouble finding the initial and final mech energy (sum of kinetic and elastic potential energy - I don't know how to find the velocity so I can't find the kinetic energy, would you set up energy equations?)

Using the spring constant I found: F=-k(d) = -200N/m (.18m) = 36 N

Elastic potential energy = 1/2kx^2 = 1/2(450N/m)(.18m)^2 = 7.29 N

The change in thermal energy = Fk(d) = (Uk)(Fn)(d)

Normal Force = mg = 24.5 N

Also, initial mech energy - change in thermal energy = final mech energy

That's pretty much all I got, any help would be much appreciated, thanks

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# Homework Help: Block compresses spring, find coefficient of kinetic friction

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