You probably feel quite happy talking about ping-pong balls or planets.

For a ping-pong ball, the weight is very small compared to the air resistance.

It begins with the sound of what is apparently a ping-pong ball being hit back and forth.

It is red in color and about the size of a ping-pong ball.

Everyone will want to have a turn throwing the ping-pong ball!

But the words bounce around in his mind like ping-pong balls, full of air.

For light objects such as a ping-pong ball, the force from the air molecules is important.

The flight crew felt themselves to be inside a ping-pong ball.

But so you've got - for me, I think we want 28 ping-pong balls.

There was nothing to see at all - like the inside of a ping-pong ball.