A particle of mass 0.1 kg is subjected to a force which varies with distance as shown in figure. If it starts its journey from rest at x = 0, its velocity at x = 12 m is

A particle of mass 0.1 kg is subjected to a force which varies with di

1.	A particle of mass 0.1 kg is subjected to a force which varies with distance as shown in figure. If it starts its journey from rest at x = 0, its velocity at x = 12 m is
Answer» `0 m//s` `40 m//s` `20sqrt(2) m//s` `20 m//s` Solution :Net WORK done by the force = area under the CURVE `F - x ` `= (4 xx 10)/2 + 4 xx 10 + (4 xx 10)/(2) = 80 J` According to work - energy theorem , `Delta KE = W_("net")` `:. 1/2 mv^2 - 0 = 80" or " 1/2 xx 0.1 v^2 = 80` or `v = SQRT(1600) = 40 m//s` .