Question

A force F = (5i +3j) acts on a particle to give a displacement d =(3I +4j)m
(a) Calculate the magnitude of displacement
(b) Calculate the magnitude of force.
(c) How much work is done by the force?
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Answer 1

Explanation:

magnitude of displacement Will be 5 this can be found by vector resultant . or in others word displacement is √ 3^2 +4^2. which is 5 magnitude of force will be calculated in simillar way . now work sice work is force . displacement costheta where theta is angle between force and displacement 5i.3i cos theta note here we are just multiplying fore into displacement since angle between i and which is unit vector is zero so cos 0 is one and hence 5i x 3i is 15 and 5i x 4j is 0 because cos 90 is 0 and angle between i and j is 90 and you can multiple so on