PHY C2: Moment and Torque

What is the Moment of a force? (Definition)

The turning effect of a force.

How is the Moment of a force defined about an axis?

As the product of the force and the perpendicular distance of the line of action of the force from the axis.

What are the units of Moment?

N m.

What is a Couple?

A pair of forces which tends to produce rotation only.

What defines a Couple?

A pair of equal and opposite forces whose lines of action do not coincide.

What is the Torque of a couple?

The product of the magnitude of one of the forces and the perpendicular distance between the forces.

What is the formula for Torque of a couple?

Torque of couple = Fd.

What is the resultant force on a body acted on by a couple?

Zero.

What is the rotational equilibrium of a body acted on by a couple?

The body is NOT in rotational equilibrium as the couple produces a turning effect.

What is the translational equilibrium of a body acted on by a couple?

The body is in translational equilibrium.