
The force shown here has a moment of about the pivot. Calculate the magnitude of the force .



Important Questions on Forces: Vectors and Moments
The asymmetric bar shown has a weight of and a centre of gravity that is from the wider end, on which there is a load of . It is pivoted a distance of from its centre of gravity. Calculate the force $P$ that is needed at the far end of the bar in order to maintain equilibrium.

State what is meant by a couple

State what is meant by torque.

The engine of a car produces a torque of on the axle of the wheel in contact with the road. The car travels at a constant velocity towards the right:
Copy the diagram of the wheel and show the direction of rotation of the wheel, and the horizontal component of the force that the road exerts on the wheel.

The engine of a car produces a torque of on the axle of the wheel in contact with the road. The car travels at a constant velocity towards the right:
State the resultant torque on the wheel. Explain your answer.

(b) The engine of a car produces a torque of on the axle of the wheel in contact with the road. The car travels at a constant velocity towards the right:
(iii) The diameter of the car wheel is . Determine the value of the horizontal component of the force of the road on the wheel.

Explain what is meant by the centre of gravity of an object.

A flagpole of mass is held in a horizontal position by a cable as shown. The centre of gravity of the flagpole is at a distance of from the fixed end.
Write an equation to represent taking moments about the left-hand end of the flagpole. Use your equation to find the tension T in the cable.
