Putt Physics Calculation 02: Pendulum Width


Hey there, golf buddies! Last time we talked about “Putt Physics,” the app that calculates your putter swing by assuming it as a pendulum motion. By doing so, it can determine the velocity of the putter head at the moment it hits the ball.

Now, based on this calculation, the way to swing the putter is super easy – just swing at an angle of θ degrees. Of course, determining the right angle can be a bit tricky, but with this method, you can adjust the putt distance to your liking.

However, the most famous way to adjust the putt distance is by adjusting the swing amplitude. “Putt Physics” also adopts this method instead of using angles.

But when it comes to displaying the swing angle, opinions are divided. Personally, I think the angle display is easier to understand, but what do you all think?

If you’re making a putt that exceeds 45 degrees, the angle display might be easier to understand. If there’s a demand for it, we’re also considering adding a display toggle function.

Now, calculating the swing amplitude from the angle θ degrees is pretty straightforward:


Using this formula, you can calculate the chord length. By halving the chord length, you can find the swing amplitude. For example, if a person is 170 cm tall and the pendulum string is 140 cm long, and they swing at an angle of θ = 9 degrees, the swing amplitude would be about 22 cm.

Even if you have a different height, you can use the same formula and method to calculate the swing amplitude.

And get this – the formula we use to calculate the swing amplitude is the same one used in other areas of physics. That’s right, folks, we’re bringing science to the green! By knowing the angle and chord length, you can predict how an object will move. It’s like magic, but way cooler.