Describe the physics of a golf ball flight off the club face

[papagrande]

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The flight of a golf ball off the club face at the moment of strike would seem to be determined, among other variables such as elasticity, by the mass of the ball, the club's force vector, and the orientation of the club face relative to that force vector. In first approximation, it seems the ball would reflected off the club face at an angle twice that of the angle between the club face and the force vector. To visualize this, rather than swinging the club, imagine throwing the ball at a surface such as club face fixed in space, and observing that the ball would reflect off of the surface at an angle mirroring the angle of incidence.

Conservation of energy, though, must account for spin. When the ball hits the surface (or the club face hits the ball) it spins more or less depending on the angle of incidence. Either the angle of reflection or the speed of the ball, or both, must be affected somehow by the energy consumed inducing spin on the ball. Baseball fielders report a base hit, with the ball bouncing rapidly towards them hops higher or lower depending on its spin, with the back spinning ball hopping higher than the top spinning ball. Pool players similarly employ side spin on their shots to affect the angle of reflection on bank shots, the cue ball spinning clockwise towards the bank reflects at an angle further clockwise than the one spinning the other way.

In this thought experiment, the limiting case seems to be the club with a 45 degree loft. If the shot direction is defined by simple reflection, the 45 degree loft would send the ball straight up, which is not experienced in a normal shot.

Any thoughts on how to calculate the direction and spin of a golf ball at launch off the club face at the moment of strike?

 

[QuantumQuest]

Hi papagrande

This is the New Member Introductions area. For your questions please use the appropriate forum. Is this a homework question?

 

[fresh_42]

Moved to classical physics.

 

[PeroK]

How did you find PF?: social media

The flight of a golf ball off the club face at the moment of strike would seem to be determined, among other variables such as elasticity, by the mass of the ball, the club's force vector, and the orientation of the club face relative to that force vector. In first approximation, it seems the ball would reflected off the club face at an angle twice that of the angle between the club face and the force vector. To visualize this, rather than swinging the club, imagine throwing the ball at a surface such as club face fixed in space, and observing that the ball would reflect off of the surface at an angle mirroring the angle of incidence.

Conservation of energy, though, must account for spin. When the ball hits the surface (or the club face hits the ball) it spins more or less depending on the angle of incidence. Either the angle of reflection or the speed of the ball, or both, must be affected somehow by the energy consumed inducing spin on the ball. Baseball fielders report a base hit, with the ball bouncing rapidly towards them hops higher or lower depending on its spin, with the back spinning ball hopping higher than the top spinning ball. Pool players similarly employ side spin on their shots to affect the angle of reflection on bank shots, the cue ball spinning clockwise towards the bank reflects at an angle further clockwise than the one spinning the other way.

In this thought experiment, the limiting case seems to be the club with a 45 degree loft. If the shot direction is defined by simple reflection, the 45 degree loft would send the ball straight up, which is not experienced in a normal shot.

Any thoughts on how to calculate the direction and spin of a golf ball at launch off the club face at the moment of strike?

For your more general question you would be better to look online for some material on the theory of golf club design.

If you analyse a club with a 45 degree loft hitting a ball using the rest frame of the club, then the ball will go approximately vertically up in that frame. But, it doesn't go vertically up in the rest frame of the tee.