Although the total potential energy converted to kinetic energy is the same for each ball, the ball on the “low road” has a higher velocity for longer, and will thus reach the end first.
This demonstration illustrates mechanical energy conservation in collisions. The number of balls that move is equal to the number of balls released, which shows the energy is conserved.
This demonstration shows Hooke’s law, in this case for the extension of a spring. Knowing that the force applied to the spring is directly proportional to the extension caused by that force, we can find a value for the constant of proportionality that relates these quantities.
This demonstration illustrates energy conservation in an object undergoing rotation, as well as centripetal force. The forces and energy types involved are (translational and rotational) kinetic energy, (gravitational) potential energy and centripetal and normal forces.
This demonstration illustrates projectile motion from a moving cart. Three kinds of projectile motion can be shown. The cart will be able to catch the ball when moving at a constant velocity on a flat surface and when accelerating down an inclined plane, but will not catch the ball when accelerating on a flat surface. These results can easily be derived from the equations of motion.