Which ball can bounce higher, basketball or volleyball? What are both balls
made of? What are they made for? Which factors determine height of bounce?
My experiments show that a basketball bounces higher than a volleyball. This is hardly
surprising, since the basketball needs to spend a considerable amount of time bouncing off the
ground, as the players move around. The volleyball is designed to be kept in the air, and
spends a considerable amount of time bouncing off hands ! It feels softer, and therefore
compresses more on contact with the ground. A greater amount of the kinetic energy is used
in deforming the body, and some is lost as heat, so the kinetic energy on rebound is
considerably less than you would obtain from a basketball. You will notice how much effort
volleyball players have to put into their game to keep the ball moving at a high speed. A
basketball would cause injury if used as a substitute for a volleyball. The 'harder' ball would
bounce off players hands with a much greater velocity. This might appear to be good, but
there would be very little time to control the ball, and the overall force of impact would
almost certainly result in injury.
Both balls can be made from a range of materials. The most expensive basketballs (match
balls) are normally made of full-grain leather, with an extra strong nylon cord, which is
wound over a butyl rubber bladder. Synthetic leather basketballs are about half the price ( 30
US dollars). Considerably cheaper are rubber basketballs with strong nylon cord
reinforcement.
By contrast, the volleyballs are smaller in diameter than basketballs. However, the range of
materials used in the construction is just as extensive. The most expensive match balls are
made of premium soft leather, usually with a floating bladder. The bladder can consists of a
butyl rubber compound, or made of a woven (soft) fabric material. For cheaper balls,
synthetic material ( synthetic leather,for example) is also used for the outer surface of the ball.
The key feature for players, however, is the softness of the ball, compared with basketballs.
There are many factors which determine the bounce height. The bounce height depends on the
ability of the ball to return the energy of deformation on impact into kinetic energy. Ideally,
the velocity of return should be equal and opposite to
the velocity of impact.
Dropped from rest, the bounce will depend on the height from which it is dropped. This is
because the kinetic energy of impact will increase. The ability of the ball to return the energy
back into kinetic energy will depend on a variety of factors, such as the
* Internal pressure of the ball
* type of fabric used in the construction of the outer surface of the ball.
* The nature of both surfaces in contact
For a perfect bounce..where all the original KE is returned the ball should reach the original
height, but this assumes no energy is used in overcoming air friction.
The bounce ratio, return height/original height, can exceed 1.0 if the ball is given a
downward velocity ...as in the case of basketball players.
I need to thank the PE Department, North Chadderton School,
England, for extremely useful information on basketball/volleyball