A box M1 M_1\,M1 of mass 5 kg and a weight M2 M_2\,M2 of mass 8 kg are joined by a light inextensible string. The string passes over a small smooth pulley at the top of a rough ramp. The ramp is inclined at an angle ϕ \phi\,ϕ to the horizontal where tanϕ=0.75\tan \phi = 0.75tanϕ=0.75. The coefficient of friction between the box and the ramp is 0.3. M1 M_1\,M1 is placed on the ramp and M2 M_2\,M2 is suspended 3 m above the floor. The system is released from rest with the string taut. Assume M2 M_2\,M2 hits the floor before M1 M_1\,M1 reaches the pulley.
Find the speed at which M2 M_2\,M2 hits the floor.