UESTION THREE a) Briefly explain what is meant by moment of a force. [2 marks] b) A uniform wheel of centre 0, 600mm diameter and weighing 5kN is being rolled along a horizontal concrete into a workshop, then jams on a rigid rectangular block of height 150mm as shown in Fig 02 below. 600 P 1501 Fig 02 Determine the magnitude of the minimum horizontal force P required to pull the wheel over the block. 16 marks)