Newton's First Law
Forces and Motion

A teaching story: constant speed with no forces acting

Teaching Guidance for 14-16 Supporting Physics Teaching

Newton's first law

Imagine taking your worst enemy in a space craft to get rid of them in the farthest corner of the universe (way beyond Sunderland). On arrival at the farthest corner, you open the cargo-hold of the space craft, position your worst enemy on the edge of the decking and give them a gentle nudge out into space. The nudge is just sufficient to send them drifting away from the craft. As they travel away they neither speed up nor slow down, since there are no forces acting upon them. As they drift away into blissful eternity, never to be seen again, you muse on the fact that their motion is a stunning validation of Newton's first law.

Newton's First Law
formalises Inertia
includes the quantity Force

Disable node explorer


Have a Physics Teaching Question?

Want to ask it in a safe, friendly, knowledgeable environment? TalkPhysics is an online community for anyone involved in the teaching of pre-19 physics.

Visit TalkPhysics