A strip of wood mass M and length l is placedon a smooth horizontal surface. An insect ofmass m starts from rest at one end of the stripand walks to the other end in time t, movingwith a constant speed.(A) The speed of the insect as seen from the ground is

The concept is that the centre of mass wouldn't change as there is no force in the horizontal direction so using equarion for velocity of centre of mass =0 and conservation of linear momentum u can solve it!! If u still dont understand just reply i will type in the solution