Lesson plan

Forces: chains of forces and combining forces

Summary
Introduce forces and how they are passed from one object to another with the coin game. Then jumping stick or catapult to show chains of forces passing between different materials. Air resistance a surprising force with good discussion. Note these are all contact forces.
Science content
Physics: Motion and Forces, Newton’s Laws, Gravity (K, 2, 6)
Procedure

Force makes things move. A push or a pull.

Start with coin game.
Summarize that there is a chain of forces between the coins that make them move in different directions.

Another chain of forces in a jumping stick toy or a catapult.
any age can make jumping stick
primaries can make torsion catapult (adult assistance needed for youngest grades)
2s and up make a more powerful tin can catapult (adult assistance needed for primaries)

Allow free play and measuring and recording of distances, before regrouping to discuss the specifics of the chain of forces.
Forces make the parts move, and also make them eventually stop.

End with counteracting forces:
We have seen that forces make things move, and that forces make things stop.
The balancing of opposite forces determines whether something will stop or slow down. When something rolls along the floor, the forward movement is balanced by the friction against the floor. When something is falling the force of gravity is balanced against air resistance, pushing up against the object.
Air resistance activity with the two paper plates works well as a demonstration with discussion.

Grades taught
Gr K
Gr 1
Gr 2
Gr 3