Moving On

A Year 10 module from the Salters’ double award science course. This module develops ideas about forces and motion in the context of road transport. It begins by eliciting some of the ideas students already have. Text activities consider the driving and counter forces involved when a bicycle starts, reaches a steady speed, or stops, also introducing the concept of inertia. A circus of experiments reinforces these ideas. Acceleration is introduced through manufacturers data on car performance. Light gate or ticker-tape experiments are used to explore the relationships between force, mass and acceleration. Applications including crumple zones and seat belts put these ideas into context. The relationship change of momentum = force x time shows the value of spreading impacts over a longer time. The value of cycle helmets is linked to the reduction of pressure achieved by spreading a force over a larger area.

Section 1: On your bike
Begins with a worksheet for students to record their ideas about forces and movement. This can be revisited after teaching the topic as a way for them to become aware how well their ideas have advanced. Picture stories introduce driving forces and counter forces and the idea that an unbalanced force is needed to change the motion of an object.

Section 2: Forces and acceleration
Engine size and performance figures for different cars provide a quantitative introduction to the relationship between force, mass and acceleration. Practical work with dynamics trolleys or model trucks leads to a statement of Newton’s second law.

Section 3: Designing for safety
Design and testing of ‘crumple zones’ on trolleys and a worksheet on seat belts leads to ideas about extending impacts over a longer time interval. Text exercises cycle helmets introduce ideas about pressure as force per unit area.

This resource includes a student sheet from the second edition of the teachers' and technicians' pack: MO12 Brace yourself.