Bell Ringer • A book weighing 1.0 newton is lifted 2 meters. How much work was done? • A force of 15 newtons is used to push a box along the floor a distance of 3 meters. How much work was done? Assignment • Pick one of the following people: Benjamin Franklin, Alexander Graham Bell, Eli Whitney, James Watt, Thomas Edison, Guglielmo Marconi, Michael Faraday, the Wright brothers, Charles Babbage • Make a list of inventions for this person • Pick one invention, draw a simple picture of it, and tell how it worked. • What types of simple machines did it have? Energy • Energy is defined as the capacity to do work. • Whenever work is done, energy is transformed from one system to another. • Energy is measured in Joules. Potential Energy • Potential Energy (PE) is called the energy of position because it results from the relative positions of objects in a system. • A stretched rubber band has PE. • Gravitational Potential Energy- depends on the mass of the object and its height relative to Earth’s surface. Kinetic Energy • Kinetic energy (KE) is the energy of the object due to its motion. • KE depends on mass… a bowling ball can do more work than a tennis ball when moving at the same speed. • Atoms and molecules have kinetic energy Mechanical Energy • Mechanical energy is the amount of work an object can do because of its kinetic and potential energy.