Strike speed on hit & before rebound ..? [Archive] - MensTennisForums.com

Strike speed on hit & before rebound ..?

ManuTOO
05-23-2008, 05:16 PM
Hello,

I'd like to know the ball speed out of the racket for any strike (example: the service), and the speed just before the rebound, to have an idea of the speed loss due to air resistance...

Anyone knows where I could find this ..?

jazar
05-23-2008, 05:28 PM
i think i remember reading/hearing/watching somewhere that like a 120mph serve by the time it got to the receiver it was at about 80mph

m9m9m9m9m9
05-23-2008, 06:17 PM
Hello,

I'd like to know the ball speed out of the racket for any strike (example: the service), and the speed just before the rebound, to have an idea of the speed loss due to air resistance...

Anyone knows where I could find this ..?

of course the instantaneous velocity of the ball is going to decrease after you strike the ball due to air resistance/rebounding effect.

but I guess the way they calculate the serve/strike speed is just using the distance between the hitting and rebounding point over the time lapse between the 2 points.
so it's something like average speed.

I remember in Dubai this year, they showed this kind of things on TV and Roddick's 220km/hr serve was just 150km/hr something when the ball reached the racket of his opponent.

ManuTOO
05-24-2008, 04:17 AM
Basically, we say that the speed of serve is halved when it reaches the opposite baseline.
So if the returner stands 2 or 3 meters after it (which is a good idea to return a 120mph serve), the ball will be at around 55mph when he returns it.

Articles about this :
- http://www.usatoday.com/sports/2003-02-24-ten-hardest-tennis-return_x.htm : "As a general rule of thumb, the ball, when it crosses the opposite baseline, is going at about half that (initial impact) speed," says Brody, co-author of a new book, The Physics and Technology of Tennis.
- http://www.tennisserver.com/wildcards/wildcards_03_10.html : see Figure 3

But this includes the loss due to the rebound, and I want to figure out the loss only due to the air resistance, thus, I need to know the speed before the rebound... So I'm still looking for info about that... :rolleyes:

lazyman
05-24-2008, 06:50 AM
it doesnt lose speed straigt away. it accelerates briefly after its hit then slows down. very briefly hough i think. i failed physics though so i dont really know

ManuTOO
06-05-2008, 05:38 AM
If it interests anyone else, I found my answers here :
http://www.advancedtennis.com/results/ballspeedmph.htm

Neely
06-05-2008, 11:11 AM
Thanks for the info :yeah:

jazar
06-05-2008, 07:13 PM
nice find