Newton's Third Law of Motion

We did a very simple science project, that turned into hours of fun! We made our own Newton's Cradle using a ruler and marbles. 

[scroll to the bottom for a free downloadable scientific method worksheet]

Newton's third law of Motion: for every action, there is an equal and opposite reaction.

Hypothesis: Ask the students to write IF and HOW the marbles will react when one is pushed into the resting marbles. Ask the same for rolling two marbles into the resting marbles, etc.

Test/Experiment: Line the marbles up on the ruler and roll ONE marble into four resting marbles

Observe/Record: What happens? (ONE marble should jump out from the other side, making a Newton's Cradle)

Test/Experiment: Line the marbles up on the ruler and roll TWO marbles into four resting marbles

Observe/Record: What happens? (TWO marbles should jump out from the other side, making a Newton's Cradle)

Let the students continue testing the hypothesis... using how ever many marbles they can (mine got pretty creative)...

Conclusion: The same number of marbles used to initiate force will expel from the other side.

The energy from the first marble is transferred and creates an EQUAL and OPPOSITE reaction. When the force is changed (the amount of marbles or how fast you roll them into the marbles at rest) the reaction changes as well.