A body of mass 2kg travels according to the relation   x(t)=pt+qt2+rt3 , where q=4 ms-2,p=3 ms-1and r = 5 ms-3. The force acting on the body at   t = 2 s  is

Given, mass,  m=2 kgx(t)=pt+qt2+rt3Velocity,  v=dxdt=p+2qt+3rt2Acceleration,  a=dvdt=0+2q+6rtAt   t=2 s,a=2q+6×r×2=2q+12r=2×4+12×5=8+60=68 ms-1 Force, F=ma=2×68=136 N