HSV B.15 - Kick shot spin effects

[johnnylawrence123456]

your videos are excellent. very helpful!!!!! keep them coming please

[DrDaveBilliards]

Thank you. FYI, I have a lot more videos and resources available on my website (see the link in the video description). I also plan to "keep them coming."

Please help spread the word about my stuff,

Dr. Dave

[sclemzoid]

btw nice slo-mo camera

[DrDaveBilliards]

Thanks. It is quite helpful for analyzing all sorts of things.

[sclemzoid]

how do you calculate (e) of a single object and not the coefficient of restitution between 2 objects (or does it not work like that?)

[DrDaveBilliards]

There are 2 objects: ball and rail cushion. It just so happens one is stationary.

COR = e = (depart speed) / (approach speed)

Dr. Dave

[sclemzoid]

yeh i get that but I mean like if two balls collided can u calculate the coefficient of restitution of one or is it just the coefficient of restitution between them?

thanks for the help

will

[DrDaveBilliards]

COR (e) is defined only for two objects:

COR = e = (normal depart speed between 2 objects after collision) / (normal approach speed between 2 objects before collision)

I hope that helps.

[sclemzoid]

ok yeh thanks thats what i thought its just that on wikipedia it was saying like e of a tennis ball is 0.87 which confused me. thanks for the help Dr.Dave

[DrDaveBilliards]

They must be assuming a "typical" tennis racket is hitting the ball at a "typical" speed in the "sweet spot."

[Hanzyyy]

wat do u mean by slick condition?

[DrDaveBilliards]

slick = low friction

A new, dry (low humidity), and clean cloth typical has less friction (i.e., it is "slick"). This changes how the table plays.

I simulated slick conditions in the video by wiping the ball with Silicone spray.

Dr. Dave