Forces in Action

These pages were conceived as aids to teaching about forces and Newton's laws of motion.

On Earth, we do not usually experience single forces in a meaningful way. There are always other "invisible" forces such as friction and gravity acting on moving objects.  These forces cannot be switched off, nor do we usually see anything obviously pushing against moving objects.  This typically leads to deep-rooted misconceptions about forces that seem to contradict Newton's laws, such as:

  • Forces are required to keep things moving.
  • In the absence of a force, a moving object will slow down and stop.

It would be wonderful to take a field trip to space, where the effects of friction and gravity can be removed.  This simulation is an attempt at the next best thing.


This page asks 10 questions intended to highlight common misconceptions about forces.  The intention is to make students more aware of preconceived ideas that might interfere with their understanding of Newton's laws.

Docking Page

Here one can control a vitual spaceship.  Use the thruster buttons (or the arrow keys on a keyboard) to apply a single force that will push the spaceship.

Questions to explore include:

  • How does the ship move while it is being pushed?
  • What happens when we stop pushing?
  • Does the ship always move in the direction it is pushed?
  • How do you bring the ship to acomplete stop?

As an additional skill test, try docking the ship with a lander.

Landing Page

This page presents a more "Earth-like" scenario, where we have an "invisible" force of gravity which can't be turned off.  This might facilitate discussion of why forces on Earth don't appear to obey Newton's laws, when in fact they do.