Forces of magnitudes 12N, 9N and 25N act on a body, as shown in the diagram. Find, correct to three significant figures, the magnitude of the force required to keep the system in equilibrium.
In this question, candidates were expected to resolve the three given vectors in their two components form (Rx) (25cos30) ( 9 cos 60) ( -12cos 45) (17.6653)
(Ry) = (25sinc30) + ( -9sin60) + ( 2sin45) = (13.1911)
If (Rx) is the resultant of the given forces, then the force required to keep the system in
(Ry)
equilibrium is - (Rx) which many of the candidates did not know.
(Ry)
The magnitude of the force =
√ (13.1911)2 + (-17.6653)2 = 22.1N
