## Overview
This topic covers the concept of force and free body diagrams. Learners study Newton’s laws of motion and the concept of linear momentum. The principle of conservation of momentum is used to solve problems involving both elastic and inelastic collisions.
## Working Scientifically
The specified practical work within this unit contains opportunities for learners to use appropriate analogue instruments to record a range of measurements; to make and record observations; keep appropriate records; to follow written instructions and to apply investigative approaches to practical work.
## Mathematical Skills
There are a number of opportunities for the development of mathematical skills in this unit. These include recognising and making use of appropriate units in calculations; using an appropriate number of significant figures; understanding and using mathematical symbols; changing the subject of an equation; solving algebraic equations; plotting two variables from experimental or other data.
## How Science Works
There are opportunities within this topic for learners to carry out experimental and investigative activities, including risk management to analyse and interpret data to provide evidence.
Learners can use and apply the concept of change in momentum to investigate the importance of crumple zones in car bonnets and air bags, and evaluate their benefits for the safety of passengers.
## Learners should be able to demonstrate and apply their knowledge and understanding of:
(a) the concept of force and Newton's 3rd law of motion
(b) how free body diagrams can be used to represent forces on a particle or body
(c) the use of the relationship F = ma in situations where mass is constant
(d) the idea that linear momentum is the product of mass and velocity
(e) the concept that force is the rate of change of momentum, applying this in situations where mass is constant
(f) the principle of conservation of momentum and use it to solve problems in one dimension involving elastic collisions (where there is no loss of kinetic energy) and inelastic collisions (where there is a loss of kinetic energy)
[[Specified Practical Work]]
• Investigation of Newton’s 2nd law