1K20.15-Weight Dependence of Friction

1k2015_weight_dependence_of_friction_2 1k2015_weight_dependence_of_friction

Video: Instructor’s video

NCSU Weight Dependence of Static Friction Demo Video

Weight Dependence of Friction Demo and Short Instruction YouTube Video

Description: This apparatus shows how the frictional force depends on weight.


  • Table
  • Friction box (see photo)
  • Newton Scale
  • Set of masses
  • String
  • Piece of fabric

Setup Procedure:

  1. Tie a string to the handle of the box, and make a loop at the other end for the scale.
  2. Make sure all the equipment is in working order.

Demonstration Procedure:

  1. You can pull the scale slowly to show the maximum force of static friction.
  2. You can also pull with constant velocity to show the magnitude of kinetic friction.
  3. By changing the mass inside the box, you can show that the forces of static and kinetic friction are both proportional to the normal force.

Tips: The newton scale needs to be pulled with a almost constant force to read it.

Concepts: This demo shows the dependence of static and kinetic friction on the normal force applied to a surface. It also shows the difference between static and kinetic friction and demonstrates friction’s dependence on the surface the force is applied to.