Chapter 8: Work and Machines

Chapter 8, Section 1, Part 1: Work

1. According to the scientific definition, why isn’t reading the textbook “work”?�(alternate: what is the scientific definition of work?)
2. Give a single-word synonym or definition for the word “kinetic”.
3. Compare the amount of work that it takes to climb a hill using the short and steep route vs using the long and not-as-steep route.
4. Work can be calculated by multiplying force times distance. Write that as a formula and then give the units of each part of the formula.
5. What is the relationship (or difference) between work and power?
6. Name a unit of power.

Chapter 8, Section 1, Part 2: Power

• What is the relationship (or difference) between work and power?
• What three things do you need to know in order to calculate power?
• What is the formula to calculate power and what are the units of power?
• If it takes me 10 seconds to lift an object with a force of 40 Newtons to a height of 2 meters, what has my “power output” been (and it what units)? By the way, I’m at an elevation of 200 meters above sea level, I weigh 86 kilograms, and the object is a rectangular solid with a volume of .6 cubic meters (at 293 degrees on the Kelvin scale). Write the formula, substitute known numbers and units, solve for the unknown, and express answer in the proper units.