Year 12 Mechanics Newton's First Law Experiments:


  • The purpose of this experiment is to clearly demonstrate Newton's first law "An object in motion, will remain in motion unless acted upon by an external force"

Teacher tips:

  • The key to effectively teaching Newton's first law is to distinguish between:
    • a body at rest
    • a body in motion

Demo set 1 (objects at rest):

  • Inertia - a clear understanding of inertia - resistance to change (equivalent to mass in linear motion) is required for Newton's first law. Please see the many inertia demos which can be found on the Y12 Inertia and Y13 inertia pages.

Demo set 2 (objects in motion):

  • spin a bob on the end of a string around your head and ask if I let this go where will it go?
  • same idea with Cat on fan:

  • The point on an object in motion remaining in motion is often best seen with astronauts in the space station. Here is an ok video, with some good ideas of demos.
  • Another example is the use or lack of use of seat belts in cars:

  • Or this animation from

  • Balloons in a car:
    • Green balloon = Helium
    • Red balloon = air


Model data:


References / other comments: