Energy Conversion in a System

While Isaac Newton is famous for his formulation of the laws of motion and the discovery of universal gravitation, he did not have a very good understanding of energy. One of the first to describe energy as a separate entity from momentum was Émilie du Châtelet, a French scientist and philosopher of the 18th century. Known for her translation of Newton’s Principia into French as well as her relationship with Voltaire, Châtelet helped determine that kinetic energy was proportional to the square of velocity and that energy in a system was conserved.

Students can explore conservation of energy with the Energy Conversion in a System Gizmo. In the Gizmo, a falling weight is attached to a spinning propeller in a tank of water. As the weight falls, the propeller spins and the water heats up. Students can then calculate the energy change of the weight as it falls and the energy change of the water to see that energy is conserved in this system.