Newton's Cradle

Never-ending fun
Easy to start
Whoosh through the air
The outside go 'Weee!" The inside say "Ow!"
On my desk, tic, tic, tic
Newton's law of movement
Science-y

Cradling the laws of momentum
Round and smooth
All you can hear is click, click, click
Down and up, up and down
Language of science
Easy to STOP.