A box of mass 20 kg is kept on a rough horizontal surface (μ=0.1
). There is a spring mass system having block of mass 20 kg and spring of spring constant 100 N/m in the box. There is no friction between block and box and spring is initially relaxed. Now, an external force of 120 N is applied on the box. Find the acceleration of the box (in m/s2
) just after applying the force.