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GGDK
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Homework Statement
A block of mass 15g enters the bottom of a circular, vertical track with a radius R = 0.5m at an initial velocity of 4/ms. If the block loses contact with the track at an angle of = 130, what is Wk, the work done by kinetic friction?
http://img94.imageshack.us/img94/1760/problem1t.png
Homework Equations
Work Energy theorem: (1/2)m(Vfinal)^2 - (1/2)m(Vinitial)^2
Work = Force * Displacement
The Attempt at a Solution
The 3 forces acting on the block: normal force, gravity, and friction.
http://img43.imageshack.us/img43/442/fbodydia.png
Before block loses contact,
Gravity has a y-component of .5(sin(40))
Normal force has a y-component of .5(sin(40)) and an x-component of .5(cos(40))
The initial kinetic energy is (1/2).015(4)^2 which equals .012 Joules.
Not really sure where to progress from here.
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