Newton's 3rd Law of Motion - Knocking Down Milk Caps

After squeezing the bottle, and ringing the bell a few times to test out Newton's 2nd Law of Motion, we removed the bell, and shortened the skewer...

...so when the bottle was squeezed (or pounded) the little paper rocket could fly right off the end.

Then we could use it to take aim at the milk caps retired from testing out Newton's first law of motion.  We stacked the milk caps into pyramids, one built of milk caps filled with play dough, and the other of empty milk caps.

And, we hot glued the bell from our strong man game, to the straw attached to our paper rocket (see the last post for details), just to give us a little more power, and noise.

One thing we noticed though, was given a lot of force, or a little, and knocking down the milk caps, or only nudging them slightly, our paper rocket always bounced back toward our launcher as the milk caps moved away.

Why was that?

Because of Newton's 3rd Law of Motion, of course.  For every action, there is an opposite, but equal, reaction.

Except when our aim was off, and we missed the milk caps entirely.  Then, we were right back to Newton's 1st Law of Motion...

...an object in motion tends to stay in motion unless acted on by an external force (like the floor, on the far side of the table).