Conservation of Angular Momentum

[Katie Morton]

Homework Statement

Imagine that you are standing on the edge of a cliff looking out over the vista… a sudden gust of wind nudges you off balance and you start tilting out over the edge of the cliff…. Yikes! You start wind milling your arms to regain your balance. A) do you rotate your arms forwards or backwards (to help you regain your balance)? B) What principle are you using in this case? C) Should you rotate your arms quickly or slowly (and why)?

Homework Equations

N/A

The Attempt at a Solution

A. I believe that the answer should be backwards so that it would cancel out the forward rotation of your body however the solution sheet for this question says it is forward. I do not understand how it could be forward because it seems to me like this would just make you fall off the cliff.

I understand B and C

 

[PeroK]

Homework Statement

Imagine that you are standing on the edge of a cliff looking out over the vista… a sudden gust of wind nudges you off balance and you start tilting out over the edge of the cliff…. Yikes! You start wind milling your arms to regain your balance. A) do you rotate your arms forwards or backwards (to help you regain your balance)? B) What principle are you using in this case? C) Should you rotate your arms quickly or slowly (and why)?

Homework Equations

N/A

The Attempt at a Solution

A. I believe that the answer should be backwards so that it would cancel out the forward rotation of your body however the solution sheet for this question says it is forward. I do not understand how it could be forward because it seems to me like this would just make you fall off the cliff.

I understand B and C

Angular momentum is not going to get your centre of gravity back behind the edge of the cliff. So, what will?

 

[Buffu]

Angular momentum won't be conserved because there is external torque acting on you by wind and gravity.

 

[PeroK]

Angular momentum won't be conserved because there is external torque acting on you by wind and gravity.

It says a "sudden gust", so the wind has no ongoing effect. And, angular momentum about your centre of gravity will not be affected by gravity.

There's a force missing here!