A path is made to a uniform density cube of mass m , and of edge a, such that when the cube rolls along the path without skidding, its centre moves along a straight line. At the top of the path a horizontal velocity of center of mass is v ₀ and the cube is in pure rolling. The static frictional force is big enough, so the cube do not slide anywhere. The speed of the centre of mass when the cube touches the lowest poi