A particle of mass 0. 1 kg is subjected to a force which varies with distance as shown in the figure. If it starts its journey from rest at x = 0, its velocity at x = 12 m is

Area between curve and displacement axis= 12×(12+4)×10 = 80 JIn this time the body acquires kinetic energy= 12mv2 by the law of conservation of energy12mv2 = 80 J⇒12×0.1×v2 = 80⇒v2 = 1600⇒ v =40 m/s