- #1
toesockshoe
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Homework Statement
The problem is that my teacher asked to solve this using kinetic energy but i doubt it uses kinetic energy... i thought it uses potential energy.
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You put your little sister (mass m) on a swing whose chains have length L and pull slowly back until the swing makes an angle ø with the vertical. Show that the wrok you do is mgL(1 - cos ø).
Homework Equations
W = integral of (F *dl))
KE=1/2 m (vf)^2-1/2m(vi)^2
The Attempt at a Solution
[tex]\int(Fdl) = \frac{1}{2}mv_f^2 - \frac{1}{2}mv_f^2 [/tex]
[tex] v_i [/tex] and [tex] v_f [/tex] are 0
so the integral becomes
[tex]\int(Fdl) = 0 [/tex]
?? what do i do now?
so my teacher makes us use integral to solve for work.
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