# Physics of golf

1. Mar 17, 2006

### sauri

A golf ball is putted too fast and rolls past the hole in a straight line, coming at closest approach to a distance d from the hole. Ignore friction and assume that golf ball moves at constant velocity.
What is the angular momentum of the golf ball about the hole?

I belive that the angular momentum is constant but its direction changes due to an external torque. Yet the equation to use is beyond me could it be d(theta)=dL/L?

2. Mar 17, 2006

### Da-Force

Actually... When we say a golf ball has a constant velocity, all the forces must add up to be zero.

Start with that by drawing components then doing a sum in the X and Y directions.

3. Mar 17, 2006

### Staff: Mentor

Consider the definition of the angular momentum of a particle:
$$\vec{L} = \vec{r} \times \vec{p}$$