Solving Monkey Swing Physics Problem

[Hothot330]

Homework Statement

http://img256.imageshack.us/my.php?image=b911om5.jpg

sin30= .50 sin60= .87
cos30= .87 cos60= .50
tan30= .58 tan60= 1.73

A 5.0 kilogram monkey hangs initially at rest from two vines. A and B, as shown above. Each of the vines has length 10 meters and negligible mass.

For parts c and d:
The monkey releases vine A and swings on vine B. Neglect air resistance.
c. Determine the speed of the money as it pass through the lowest point of it's first swing.

d. Determine the tension in vine B as the monkey passes through the lowest point of its first swing.

Homework Equations

Centripetal force? m(v^2/r)

The Attempt at a Solution

Completed parts a and b. Force diagram and tensions in each vine before release. T1= 9N and T2= 5.13N

I'm not sure as what I am to do... I'm thinking that it has something to do with centripetal force but not sure cause he is swinging.

 

[mgb_phys]

Part C - the easiest way is probably conservation of energy.
Calculate the difference in height between it's initial position and the position when the vine is at it's lowest point. PE = m g h and KE = 1/2 m v^2

Part D - don't forget you also have the weight of the monkey.

 

[Hothot330]

that makes sense, thanks for the tip. Never would have thought to use conservation of energy.

 

[mgb_phys]

Never would have thought to use conservation of energy.

It's always a good bet - it can't necessarily answer all questions (part D for instance) but when it's right it's right! And is generally simple, you don't have to worry about angles and vectors etc.

 

[Pandasaur]

ahh but how do you calculate the height? Are you sure the tension in both a and b are correct hothot?