Unit 6: Work and Energy
Energy is the capacity of a physical system to perform work. It plays an essential role both in everyday events and in scientific phenomena. You can probably name many forms of energy from that provided by our foods to the energy we use to run our cars to the sunlight that warms us on the beach. Not only does energy have many interesting forms, but it is involved in almost all phenomena and is one of the most important concepts of physics.
Energy can change forms, but it cannot appear from nothing or disappear without a trace. Thus, energy is one of a handful of physical quantities that we say is conserved.
Completing this unit should take you approximately 14 hours.
6.1: Work and Kinetic Energy
Watch this lecture series, pausing to take notes, before moving on to the reading below.
Read sections 7.1 and 7.2 of "Chapter 7: Work, Energy, and Energy Resources" (pages 221 to 228).
In this animation, you will vary the angle between the two vectors and observe the effect on the dot product.
Work on solving problems 1, 2, and 3 from SAC122. The solutions are available, but make a serious attempt to solve the problems before looking at the solutions.
6.2: Conservative Forces and Potential Energy
Read sections 7.3 and 7.4 of "Chapter 7: Work, Energy, and Energy Resources" (pages 228 to 236). Look over the corresponding conceptual questions on page 254 to test your understanding of the sections.
6.3: Conservation of Energy
Read sections 7.5 and 7.6 of "Chapter 7: Work, Energy, and Energy Resources" (pages 236 to 243). Look over the corresponding conceptual questions on pages 254 and 255 to test your understanding of the sections.
Work on solving problems 4, 5, and 6 from SAC102. The solutions are available, but make a serious attempt to solve the problems before looking at the solutions.
6.4: Power
Read sections 7.7, 7.8, and 7.9 of "Chapter 7: Work, Energy, and Energy Resources" (pages 243 to 251). Look over the corresponding conceptual questions on page 255 to test your understanding of the sections.
Work on solving problems 1 through 4 from SAC124. The solutions are available, but make a serious attempt to solve the problems before looking at the solutions.