Physics 1 - Chapter 8
Energy
Terms & Objectives

Note: The following terms and objectives are based on the Indiana Standards 2000 for Physics 1. You may download the complete physics standards by clicking here, or view the standards relevant to Chapter 8 - Energy here.

New Terms in Chapter 8:

actual mechanical advantage	Joule	power
efficiency	gravitational potential energy	theoretical mechanical advantage
energy	Watt	kinetic energy
Law of Conservation of Energy	mechanical energy	potential energy
fulcrum		work

Chapter 8 Objectives:

When you have completed Chapter 8, you should be able to:

• Work & Power
  1. ... calculate work done by a constant force acting:
     • in the direction of motion of an object.
     • opposite the direction of motion of an object.
     • perpendicular to the direction of motion of an object.
     • in the case where the object does not move.
     • and recognize that a force does not necessarily do work.
  2. ... define power and calculate power given work and time.
• Work & Kinetic Energy
  3. ... recognize kinetic energy as energy of motion and calculate the kinetic energy of an object.
  4. ... discuss the relation between work done by the net force on an object and the object's kinetic energy, and use this relation to answer questions and solve problems, such as:
     • ... explain the relation between the speed of a car and its stopping distance in terms of the kinetic energy of the car.
  5. ... recognize work and energy as scalar quantities.
• Potential Energy
  6. ... recognize potential energy as energy due to position or arrangement.
  7. ... distinguish between conservative and non-conservative forces.
  8. ... calculate the gravitational potential energy of an object near the surface of the earth.
• Conservation of Energy
  9. ... state the Law of Conservation of Energy.
  10. ... use the Law of Conservation of Energy to explain conceptually how energy is transformed from one form to another in simple situations such as:
      • a falling object.
      • an object thrown into the air.
      • a simple pendulum.
  11. ... apply the Law of Conservation of Energy to problems involving free fall, elastic collisions, etc.
• Simple Machines
  12. ... apply the Law of Conservation of Energy to the operation of simple machines such as:
      • an inclined plane.
      • a lever (3 types).
      • a single or multiple pulley.
  13. ... calculate the mechanical advantage of a simple machine, and distinguish between theoretical and actual mechanical advantage.
  14. ... calculate the efficiency of a simple machine.
  15. ... explain, in terms of conservation of energy, why the efficiency of a machine cannot exceed 100% - in other words, explain why a "perpetual-motion machine" cannot be built.

Possible Misconceptions to Correct:

Do you believe that any of the following statements are true? They AREN'T! When you finish Chapter 8, you should understand that each of these statements is FALSE, and WHY.

• WRONG: Work = Force times distance.
• WRONG: Momentum and kinetic energy are essentially the same thing.
• WRONG: Impulse and work are essentially the same thing.
• WRONG: Potential energy = mgh always.
• WRONG: A car traveling at twice the speed of another requires twice the distance to stop.
• WRONG: A perpetual-motion machine could be constructed.