EXAMPLE 3: King Kong's Pendulum 
Question 

While climbing the Empire State  Building, King Kong peaks into one of the corporate windows, and sees a poster with Tarzan swinging from a vine. Our furry friend decides he'd much rather be swinging from vines instead of hanging outside of skyscrapers When King Kong is swinging from a vine, what forces are acting on him? 


Hints 

The forces we discussed were 

1.gravity

2.normal

3.friction

4.push or pull 


Solution 
1. We assume that King Kong has travelled to the jungles on Earth, so he still experiences the Earth's gravitational force, Fmg.

2. The overgrown gorilla is not in contact with any surface, so there is no normal force. 

3. Again, he is not in contact with any surface, so neither static friction

nor kinetic friction is exerted on him. 

4. No one or thing is pushing or pulling on King Kong (and who or what

would want to?), but there is a tension T in the vine holding him up. 



Explanation on FBDs

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