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DkMuse
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Homework Statement
George of the Jungle, with mass m, swings on a light vine hanging from a
stationary branch. A second vine of equal length hangs from the same point,
and a gorilla of larger mass M swings in the oposite direction on it.
Both vines are horizontal when the primates start from rest at the same
moment. George and the ape meet at the lowest point in their swings.
Each is afraid that one vine will break, so they grab each other and hang on.
They swing upward together, reaching a point where the vines make an
angle of 35.0° with the vertical.
Find the value of the ratio m/M.
Homework Equations
Angular Momentum - L = mvr
Potential Energy - U = mvh
Kinetic Energy - K = 1/2 mv^2
The Attempt at a Solution
When both the man and ape start from rest the potential energy is
U = mgh, where h = r-rcosθ, r being the length of the vine
at 0°, cos 0° = 1, r-r =0
so U = mg
The knetic energy at the bottom given by K = 1/2 mv^2
setting an equality of K=U
1/2 mv^2 = mg
v= sqrt 2g
This would apply to both the man and the ape.
vM = vm = vf - right?
The potential energy of the man/ape system would be
U = (M+m) g r(1-cos 35°)
The kinetic energy of the man/ape system would be
1/2v^2(M-m)
So
1/2v^2(M-m) = (M+m) g r(1-cos 35°)
would be one equation for energy
and
Mvr + mvr = (M+m)vr
would equate angular momentum
... How do I continue to get a ratio of m/M?