- #1
jcfor3ver
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Homework Statement
The rope of a swing is 2.90 m long. Calculate the angle from the vertical at which a 81.0 kg man must begin to swing in order to have the same KE at the bottom as a 1450 kg car moving at 1.05 m/s (2.35 mph).
Homework Equations
KE=1/2mv^2
PE=mgh
SOH CAH TOA (trig reference)
The Attempt at a Solution
I made a right traingle from the mass at the beginning of its journey to the very bottom (middle of the rope). Then I found the KE at the bottom which is the KE of the car. Then I took 1/2mv^2 and set it equal to the KE of the car so I could find the velocity of the man.
Then I found the height of the starting position of the man to get his gravitational PE by setting mgh=to the KE of the car to find h.
What do I do after this? I am confused on how to find this optimal angle.