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

The work done is equal to the area of F-x graph. Hence W=12×4×10+4×10+12×4×10  =80 joule The change in velocity is equal to work done. so 12mv2=W  or  12×0⋅1×v2=80 or V2=1600  or  V=40m/s