AST 2002 Lecture Notes - Lecture 12: Photon, Angular Momentum, Conservation Law
Document Summary
Ast 2002: conservation laws, momentum=mv, angular momentum = r x mv, energy c. i. Even when newton"s laws fail, conservation of energy holds: types of energy, kinetic a. i. Light: gravitational potential energy, on earth, it depends on a. i. The distance an object could potentially fall a. iv. In space, an object or gas cloud gas more gravitational energy when it is spread out than when it contracts a. iv. 1. A contracting cloud converts gravitational potential energy to thermal energy: how do gravity and energy together allow us to understand orbits? b. i. Total orbital energy (gravitational & kinetic) stays constant if there is no external force b. i. 1. The collective kinetic energy of many particles b. i. 2. a. i. 1. Thermal energy is related to temperature but is not the same b. i. 3. Temperature measures the average kinetic energy of the particles b. i. 3. a. b. i. 3. b. Kelvin is used to measure temperature in science.
