Investigate the relationship between the rotation of mechanical systems and the applied torque

Torque : It is a measure of the force that can cause an object to rotate about an axis.

It is also known as moment or moment of force.

  • As you can see the force F can be broken up into two components.
    • Fcosθ, which is parallel to the rod and cannot rotate the rod.
    • Fsin θ, which is perpendicular to the rod and contributes to the rotation.
  • r is the radial distance from the axis of rotation to the point of application of the force
    • As the r is increased , the moment or torque produced increased.

                    Thus torque produced is

                    Where  ‘’ denotes the component of the force which is perpendicular to the radial distance (of rod)


Extract from Physics Stage 6 Syllabus © 2017 NSW Education Standards Authority (NESA)