11/14/08

Post date: Nov 14, 2008 2:41:45 AM

Bell Activity: Wait to get your test back. You have 20 minutes to check your calculations and finish anything you couldn't yesterday.

    • Work

      • What does "work" mean in your lives?

      • In physics, work = Force * distance, measured in Joules (J)

        • Force must be in same direction as motion for work to be done

        • Example: Lifting a weight vs. holding a weight.

        • Example: Stepping up on a chair

      • If force is NOT in same direction, first find the component of the force in the direction of the objects movement

        • Example: Lawn mower

        • Practice: Page 202: 7

    • Power

      • What does "power" mean in your lives?

      • In physics, power = work / time, measured in Joules per second (J/s) or Watts (W)

        • Example: Page 203: 9

        • Practice: Find your inner power!

          • Step up and down on a chair 10 times in a row while a partner times you. Calculate the total work you do and divide by the time it took you to do it to find your power.

          • Answer the following questions: 1. How many 60 W light bulbs could you power? 2. How many of you would it take to power a 40,000 W care engine?