I love playing ping
pong, but I always, ALWAYS dent the tiny plastic balls. I was playing ping pong
with my friend after school today, and I dented yet another ball. I was
grumbling that I would have to go out and buy new ones, when she showed me how
to make them round again. All you have to do is put the balls in a bucket of
warm water. I know, I thought she was crazy when she first told me too. But, it
actually works! Maybe if I explain the science behind it, you’ll believe me.
A brilliant French
scientist named Jacques Charles figured out that if, while the pressure on the
gas is the same, the temperature increases, the gas will expand. If the
temperature decreases, the gas will take up less space. Naturally, this law is
called Charles’s Law. Now you think I’ve totally lost it. Why am I talking about
a science law when I’m supposed to be admitting that the ping pong trick
doesn’t actually work? Actually, the two things are completely related. When
you put the dented ping pong ball in warm water, the temperature of the gas
increases because the water on the outside is heating the gas (or air) inside.
Charles's law states that when a gas’ temperature is increased, it will take up
more space. The pressure has to remain constant, or course. In the ping pong
ball situation, as the air inside the ping pong ball heats up, it expands to
take up more space, according to Charles’s Law. Because it has to take up more
space, it has to force the dented plastic of the ball out to create space
inside, and makes the ball round again. See, I’m not crazy! Try it and see for
yourself!
