CEM 141 Lecture 5: CEM 141 Lecture 5 Notes
Document Summary
Shot alpha particles at a sheet of gold and deduced the atom had a positive center. Most of the alpha particles went through the foil signifying the atom is mostly empty space. Same as electrostatic force (can be used interchangeably. We are only considering electric fields between particles. Like charges repel and opposite charges attract. If there is no motion gravity= electrostatic force. There must be pushing/pulling in opposite directions. We do not know- definitions are often circular. Change in matter leads to a change in energy. Changes in energy are always caused by changes in force. Energy is conserved; can transfer or transform. System: point of the universe being studied. Temperature is used to measure energy change. All of these types of energy fall into the two types of energy at a molecular level. Energy associated with the position of a system of objects in a field. Cannot have potential energy without a field.
