Newton’s 1st and 2nd laws – a senior physics unit

Newton’s 1st and 2nd laws is a senior physics unit. It is most suitable for students who have already learnt about the fundamentals of motion such as distance, speed, velocity and acceleration


The everyday use of self-driving cars may still be science fiction but the basic laws of motion that describe how cars change speed and direction while avoiding – or colliding with – obstacles, have been known for over 300 years.

In space, with no air and little gravity, small forces maintained for long periods can accelerate objects to huge velocities. That’s how the Dawn spacecraft, under the gentle thrust of its ion engines, has got to Ceres in the Asteroid Belt.

In this unit you will investigate the following:

  • Newton’s first law of motion – the law of inertia – and how inertia relates to car safety.
  • How to draw free body diagrams and why they are used to analyse forces.
  • Common misconceptions about the law of inertia and how they can be corrected by clear science communication.
  • Newton’s second law of motion: What is the relationship between force, mass and acceleration?
  • How does the relationship apply when there are many forces acting on an object?
  • What velocity will Dawn reach if it keeps its ion engines on for a year?
  • How do you make a jet-propelled drink can?

Science and society profiles a rocket scientist, and as a societal issue we consider some issues surrounding self-driving cars.