PHYS124 Lecture 1: Lecture 1 Oct 9, 2015 10_09_45 AM

• School: University of Alberta
• Department: Physics
• Course: PHYS124
• Professor: Sharon Morsink

Document Summary

Work done = area under the force vs. displacement curve. Gravitational, electro magnetic, elastic potential, kinetic energy, heat energy, chemical energy, nuclear energy. Force of gravity has ability to do work. Forces can be classi ed into either conservative or non conservative. Conservative force: no net work done when the object returns to its start location. Non conservative force: depends on path an object takes rather than objects position. Remember: energy is only conserved for closed systems. For external forces, like friction, we must include the work done against friction in order to calculate the amount of energy lost from the system. Work done against friction is converted into heat and sound energy. When ball hits the ground, energy is wasted as other forms of energy* Work done by gravity is same in both cases (non zero) but friction is greater for the longer run down mountain. Some energy lost converted to heat, sound, vibrations, etc.