Lesson plan

Forces: chains of forces and combining forces

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.
Science content
Physics: Motion and Forces, Newton’s Laws, Gravity (K, 2, 6)
Physics: Energy forms, Conservation of Energy (1, 3, 4, 5)

Forces make things move, or make moving things stop. Another name for a Force, which is easier to envision, is a Push or a Pull.

Start with coin game, either as a demonstration or for students to do at their desks.
Summarize that there is a chain of forces between the coins that make them move in different directions.
The size of the coin changes how much force is transferred to another coin.
The force of friction changes how coins move on a smooth surface vs a carpet.

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

Allow free play and optionally 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 slides 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.


Add electrostatic force as a non-contact force: do as a demo with one of the students (the one with the best hair for it)

Grades taught
Gr K
Gr 1
Gr 2
Gr 3