Q 8). A box of mass 120 kg is placed at the top of an inclined plane, which makes an angle of 35 degrees to the horizontal and is then released. If the coefficient of static friction between the box and the plane is 0.57, prove that the box will start sliding down the plane, unassisted by any external push. If the coefficient of kinetic friction is 0.43, calculate the acceleration of the box, and hence the time taken for it to slide 4 m along the plane.

Fig: 1