Two forces 100N and 60N act on an object of mass 10kg as illustrated in the diagram above. Neglecting friction, calculate the acceleration of the object.

  • A 4.0\(ms^{-2}\)
  • B 13.4\(ms^{-2}\)
  • C 16.0\(ms^{-2}\)
  • D 22.6\(ms^{-2}\)
waec 2017physics

The correct answer is B. 13.4\(ms^{-2}\)

Resolving 100N into horizontal and vertical 

100 sin45 = 0.7071 * 100 = 70.71

100cos45 = 70.71

Vertical forces = 100 - 70.71 â†’ 29.29

Horizontal force = 70.71 + 60 â†’ 130.71

Resultant of vertical and horizontal forces using pythagoras thoerem

Resultant force (F) = m * a 

a = F/m â†’ 133.9/10

a = 13.4

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