What do we know about forces?

1. Let’s think back!

• When the rocket is moving in space, what happens if the engine is turned off? What happens if it stays on? How does the rocket stop?

• What does this tell you about the forces on the rocket? When are the forces balanced?

• Can you describe when the rocket is moving and has balanced forces? Can you describe when the rocket is moving and the forces are not balanced?

• Think about the forces acting on Percy. At what points in his story is he not moving? What can you say about the forces acting on him at these points?

• When is he moving at a steady speed? What can you say about the forces at these points?

• When is he accelerating? When is he decelerating? What can you say about the forces at these points?

2. Parachute Percy

3. Odd one out

• Which situation do you think is the odd one out? Why have you chosen this one?

• What can you say about the forces in each situation? Can you describe if they are balanced or not?

1. A motorbike doing a steady 60mph on the motorway

2. A boy going faster and faster downhill on his scooter

3. A supermarket trolley moving steadily along the aisle

4. A supermarket trolley that is not moving.

4. Plenary

• How could you complete this sentence?

• What do you know about forces on moving objects?

• What evidence can you think of to support your choice of sentence ending?

• Does the whole group agree with the sentence ending you have chosen? What is the best ending your group can create?

The forces on a moving object are balanced when ….