Use trignometry to compute how much higher he is at the 35 degree angular position that at the bottom of the swing. Call that distance h. You will need to subtract a cosine term from the length to get h. This is something you should be able to do.
Then use conservation of energy to get the speed at the bottom:
m g h = (1/2) m v^2
v = sqrt (2 g h)
Tarzan swings on a 27.0 m long vine initially inclined at an angle of 35.0° with the vertical.(a) What is his speed at the bottom of the swing if he starts from rest?
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