First Law of Motion: Objects in motion tend to stay in motion unless acted upon by an external force. Force is a push or a pull, like pulling a wagon or pushing a car. Gravity is a force that attracts things to one another. Gravity accelerates all things equally. Which means all things speed up the same amount as they fall.

Materials: ball

[am4show have='p8;p9;p11;p38;p10;p37;p72;p92;' guest_error='Guest error message' user_error='User error message' ] What happens when you kick a soccer ball? The ‘kick’ is your external force. The ball will continue in a straight line as long as it can, until air drag, rolling resistance, and gravity cause it to stop.

Find out more about this key principle in Unit 1 and Unit 2.



Download Student Worksheet & Exercises

Exercises 
  1. What is inertia?
  2. What is Newton’s First Law?
  3. Will a lighter or heavier race car with the same engine win a short-distance race (like the quarter-mile)?
[/am4show]

Have a question ?

Tell us what you're thinking...