Science Buddies: "Ask an Expert"

how high can a soccer and volley ball bounce?

Ley,

Can you be more specific in your question? Are you asking how high will it bounce when dropped from a certain height? Or are you asking what it the maximum possible bounce height? Two quite different questions, both of which are interesting questions.

First, have you ever noticed that a ball never bounces higher than the height from which is was dropped? This is an example of conservation of energy... minus any losses it encountered during the bouncing process. Some of that energy lossed went out as sound energy, the sound of the "BOING" bounce. Some was converted to heat in the ball or the air inside the ball. Notice that when the ball is allowed to bounce over and over that it bounces less and less high? That's the energy going away. This would make a good science fair type experiment, measuring the loss of energy in each bounce by measuring the difference between the original hieght and the bounce height.

If you're interested in the second question, how high will it bounce if you dropped the ball from a really, really high place... well that's another really interesting thing... because the ball can't keep falling faster and faster because there is air in the way. The air slows the ball down. The faster the ball falls, the more the air gets in the way, increasing "aerodynamic drag" (this is a good online search keyword) until the drag force exactly equals the weight of the ball... at which point the ball stops accelerating, and falls at the same speed, called the "terminal velocity" (another online search keyword).

So, tell us... what kind of experiment do you want to conduct to learn your answer? How can we help you?

By the way... do you want to see something really weird and cool? try droping two balls together, at the same time, one on top of the other, touching each other... especially a small ball on top of a big ball, like a tennis ball on top of a basket ball. Try the experiment and let us know your results! (Hint: Do it outside for safety reasons.)

Hi,

I took the implied question to be "which bounces highest?" If so, I'd drop them from some sensible height (10 ft?) while someone else determines the height of the bounce. Estimating this is a bit tricky so, whatever technique you decide on, I'd be sure to use many trials.

ley wrote:how high can a soccer and volley ball bounce?

i think that is a very good question

thanks for your reply.... Well, my experiment is about three balls,(basketball, soccer ball and volleyball), dropping each one of them on the same height, and i want to know which of them will bounce the highest....

Be sure to control the variables, and repeat the experiment.

The balls must be dropped on the same surface, at the same angle. Creating some kind of device that drops them the same way is going to be more reliable than dropping them by hand (which can introduce error not only in height, but you might "push" the ball toward the ground by accident, add spin or do other things)


You may also want to experiment with multiple tennis balls, basketballs and soccer balls, if you intend to speculate on why a given ball bounces higher than another. The variation between a given type might give you clues to the science behind the observations.