I need to calculate the angular velocity/acceleration of a golf swing.

Question

because the golf swing is a double pendulum system (being chaotic), uniform circular motion formulae cannot be applied. i am doing an assignment on the physics of the golf swing and need to calculate these to eventually work out the total torque and ext impulse of the system. PLEASE HELP!!

Answer 1

You've got to start over:

1. A golf swing is NOT a double pendulum system, it is much more complicated than that, with pivot points and more than 2 places and forces due to muscles as well as to gravity.

2. There is no reason to believe that a golf swing is a chaotic system.

3. Since you are not in a position to model the full complexity of a golf swing, why not assume uniform circular motion as your first order approximation? Abandon it if it becomes inadequate, but at the level that you are working, there is no reason that it should.

4. To first order, you can assume that the shaft of the club is weightless - that all the mass is in the head. So what is the weight at the head? How long is the golf club?

5. You can get the velocity of the head just before it hits the ball in various ways:

A. You can look at videos or high speed stills of pros swinging to actually measure the velocity.

B. You can determine empirically the coefficient of restitution of the golf ball

http://en.wikipedia.org/wiki/Coefficient...

and use the the golf ball velocity to compute what the velocity of the head of the club was. (For a pro, typically 160 mph; for an amateur more like 130)

http://www.titleist.com/technology/launc...

C. You can look at what other researchers have done:

http://www.scigolf.com/scigolf/myths/myt...

http://www.tulane.edu/~sbc2003/pdfdocs/0...

D. The linear acceleration, work done, etc. are all fairly straightforward. But if you are going to talk about torque, then you have to select an axis. Even if there were only two pivot points, which would you use?