# Energy

Student Learning Objectives
Lessons / Lecture Notes
Important Equations
Example Problems
Applets and Animations

Student Learning Objectives

• To understand the concept of work and how it is calculated.
• To understand the concept of energy -  what energy is and how it is transformed and transferred.
• To learn about the relationship between work and kinetic energy through the work-kinetic energy theorem.
• To understand the concept of potential energy.
• To differentiate between conservative and non-conservative forces.
• To understand and use the law of conservation of energy.
• To recognize transformations between kinetic, potential, and thermal energy.

Lessons / Lecture Notes

The Physics Classroom (conceptual)

PY105 Notes from Boston University (algebra-based):

Introductory physics notes from University of Winnipeg (algebra-based):

HyperPhysics (calculus-based)

PHY2048 notes from Florida Atlantic University (calculus-based):

PHY2043 notes from Florida Atlantic University (calculus-based)

General Physics I notes from ETSU (calculus-based)

Important Equations

Example Problems

Problem 1
In the figure, a frictionless roller coaster crosses the first hill of height h = 65 m with a speed vo = 22.0 m/s. (a) What is the speed of the coaster at point A? (b) How high will the coaster go on the last hill (beyond point B), which is too high for it to cross? (Solutions)

Problem 2
A 3.00-kg block starts at a height h = 65.0 cm on a plane that is frictionless and has an inclination of 30.0o.  Upon reaching the bottom, the block slides along a rough horizontal surface with coefficient of kinetic friction of 0.25.  How far does the block slide on the horizontal surface before coming to rest? (Solutions)

Applets and Animations
 Friction Learn how friction causes a material to heat up and melt. Rub two objects together and they heat up. When one reaches the melting temperature, particles break free as the material melts away. The Ramp Explore forces, energy and work as you push household objects up and down a ramp. Lower and raise the ramp to see how the angle of inclination affects the parallel forces acting on the file cabinet. Graphs show forces, energy and work. Energy Skate Park Learn about conservation of energy with a skater dude! Build tracks, ramps and jumps for the skater and view the kinetic energy, potential energy and friction as he moves. You can also take the skater to different planets or even space! Roller Coaster The Roller Coaster model explores the relationship between kinetic, potential, and total energy as a cart travels along a roller coaster.  Users can create their own roller coaster curve and observe the resulting motion. Pendulum Energy The Pendulm Energy Model shows a pendulum and associated energy bar charts. Users can change the initial starting point of the pendulum. (Interrupted) Pendulum This applet displays a pendulum oscillating back and forth. The user can vary the height of a pin so that the pendulum’s path is interrupted. Energizer The Energizer model explores the relationship between kinetic, potential, and total energy.  Users create a potential energy curve and observe the resulting motion.