Asked by Lindsay

A youngster shoots a bottle cap up a 15.0° inclined board at 1.92 m/s. The cap slides in a straight line, slowing to 0.95 m/s after traveling some distance. If the coefficient of kinetic friction is 0.35, find that distance.

I still don't quite understand this one. How do I use cos 15 to find the acceleration? I thought I only needed sin 15...
Answered by drwls
You use cos 15 to get the fraction force and sin 15 to get the energy used working against gravity. You don't need to solve for the acceleration. Use an energy method. It's easier that way.

The initial kinetic energy equals work done against friction and gravity.

(1/2)MV^2 = MgX*sin 15 + Mg*muk*cos 15*X

Cancel the M's and solve for X.
muk is the coefficient of kinetic friction.
Answered by Lindsay
What is V, in this case?
Answered by Lindsay
A youngster shoots a bottle cap up a 15.0° inclined board at 1.92 m/s. The cap slides in a straight line, slowing to 0.95 m/s after traveling some distance. If the coefficient of kinetic friction is 0.35, find that distance.

So I get that (1/2)MV^2 = MgX*sin 15 + Mg*muk*cos 15*X, but what is V, in this case?
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