# Physics Question -- Throwing A Tennis Ball

#### Raul_SJ

##### Legend
Lets assume distance from baseline to baseline is 80 feet. And there is a 10 foot back fence 20 feet behind the baseline.

A six foot tall man standing at the baseline throws a tennis ball that lands at bottom of the fence. Total distance of throw = 100 feet.

If his goal is to clear the 10 foot fence, where would the throw need to land? How much farther beyond 100 feet does he need to throw?

Any other info needed to solve this? (angle of projectile, etc).

#### travlerajm

##### Legend
Due to air drag, the ball lose at least half its initial horizontal velocity and will be falling at an angle about twice as steep as the launch angle. So assuming the ideal launch angle is roughly 30 degrees from horizontal, the ball would descend past the fence at about 60 degrees from horizontal. So you'd only need your well-aimed throw to land about 6 feet past the base of the fence.

It would take a little bit more math to calculate the ideal launch angle exactly.

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#### sureshs

##### Bionic Poster
All 2D projectile math without air dampening uses only 2 variables when phrased as throwing from the ground: the launch angle and the launch velocity vector. So that is actually 3 numbers. Add to that the height above ground of the launch, or add it in later. The independent variable is either time or the horizontal distance, which are related though the horizontal component of the velocity which is assumed constant. Then, another equation for the same time is obtained by computing the vertical motion which is under a negative acceleration of g and initial vertical component of the velocity.

#### dgold44

##### G.O.A.T.
????
I think you need to look at newton as he figured all this out centuries ago ;and in my humble opinion ;was the greatest genius to ever live
Many factors like wind speed , amount of air in ball , direction of wind , angle of throw , velocity of release of arm and wrist etc

It’s physics 101 and I don’t remember anything

#### Harry_Wild

##### Legend
The easiest throw would be a high lob that pasts the 10 foot fence at the peak of the arch or just before like a football 3 point field goal kick that just made it past the horizontal post.