After his famous experiment of dropping cannon balls from the Tower of Pisa, Galileo was determined to fully describe the physical laws of falling bodies. However, freefall happened too quickly to be accurately measured using available methods, which could be as crude as counting heartbeats. Galileo realized that he could slow down the motion of falling bodies by sliding or rolling them down an inclined plane. The discoveries that resulted from these experiments form the underpinnings of our understanding of force, acceleration, energy and gravitation. Potential energy (PE) is the energy an object has due to its position or the configuration of its parts. Kinetic energy (KE) is the energy an object has due to its motion. When a moving object runs into a relaxed spring it will slow down, come to rest momentarily, before accelerating in a direction opposite to its original direction .While the object is slowing down, it will compress the spring. As the spring is compressed, the kinetic energy of the block is gradually transferred to the spring where it is stored as potential energy. The potential energy of the spring in its relaxed position is defined to be zero. The potential energy of the spring in any other state can be obtained from Hooke's law.
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.