How to calculate where a tennis ball will land?

Jimmy D.: How to calculate where a tennis ball will land?
I throw tennis balls for my sister to hit on the weekdays and have been wondering, how can I tell where the tennis ball will land after she hits them with her racket? What formula and physics are involved?
Or the direction it will go in.

Answers and Views:

Answer by Tom Sparky
You’re lucky you have one of the best machines for those calculations sitting on top of your shoulders. The mind can very quickly estimate where the ball will land. The more experienced you are, the quicker and more accurately your mind will make those estimations.

Answer by Error
look at the position of the racket when your sister hits the ball, the position its facing is where the ball will probably go.

Answer by Jimbo
u can tell by the way she is facing which direction it will go but u cant tell the distance usually

Answer by Bobby
This would be very hard to calculate accurately. Factors include air resistance, wind direction, type of ball, how hard it is hit, amount of spin put on the ball, whether the spin is topspin, sidespin or underspin, how tight the strings are, height of the ball when struck, and maybe a few other factors. I give up.

Physics teacher.

Answer by aaron c
You can only tell by using your brain and gaining practice in watching shots and watching where they land. It is to much information in to short of a time for you to calculate where the ball is going to land.

Similar to how somebody 50 yards away can throw you a baseball and you will instantly know where it is going to end up and make the catch, even though you didn’t think about it.

P.S- shoulder turn, etc can be misleading. This is just a skill acquired over time.

Answer by F/H Slice
This is a very open ended question. Here are a few aspects that have the most direct effect on where your sisters ball will land:

How hard she is swinging;
How she is swinging, whether or not she swings low-high, or high-low
What racquet she is using and the tension of the string.
The angle of her racquet face at contact. (Is the bottom edge leading when she hits or top edge)
Location of the racquet on the ball at contact. (either right behind the ball, or on the inside or outside)
What type of spin she is using. (topspin or backspin)
Weather conditions (wind)
The only physics I’ve ever used while teaching is that there are 2 things that keep the ball from travelling too far, spin and gravity. No formulas in tennis though.