Answer:
Centre of gravity is a theoretical point in the body where the total weight of the body is thought to be concentrated. In a uniform gravitational field, the centre of gravity is identical to the centre of mass. Yet, the two points do not always coincide.
The sugar cube experiment in the laboratory gives us a good approximation of the amount of energy that can be derived from the sugar cube because the amount of energy is neither created or destroyed, it is just converted to another form. If the energy from the sugar cube is converted to other form in the lab then, it is possible that same amount of energy will be derived.
Initial velocity = 25 m/s, angle 60°
sin (60°) = opposed leg / hypothenuse = Vertical velocity / Initial velocity
=> Vertical velocity = initial velocity * sin (60°) = 25 m / s * 0.866 = 21.65 m/s