Warmup 12: Kinetic Energy and Power

Course

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The first three questions refer to the material you were to read in preparation for the lesson. Questions one and two require you to write a three or four sentence response. Number three is a multiple choice question. Click in the appropriate circle. Questions 4 is your opportunity to suggest what we should emphasize today and how.

You may change your mind as often as you wish. When you are satisfied with your responses, click the SUBMIT button at the bottom of this page.


1. Using residential electric power rate information available, (or call your local power company), estimate how much it would cost to run a 100 W light bulb continuously for a month somewhere near your hometown.

Also, how many joules will that light bulb consume in that time?

(Please state the power rate you use for your estimate, and show the important steps you make.)



2) A force of 100 N, acting over a distance of 10 meters, increases the kinetic energy of a moving object by 500 J. This information is sufficient to conclude that

  1. the object was accelerated
  2. there was friction present
  3. the potential energy changed
  4. all of above



3) Some athletes can put out as much as 700 watts in short bursts. If you could sustain such an energy output for 1 hour, how fast would you be travelling at the end of that time period? State any assumptions you have made to solve the problem.


4. Below is a space for your thoughts, including general comments about today's assignment (what seemed impossible, what reading didn't make sense, what we should spend class time on, what was "cool", etc.):




You may change your mind as often as you wish. When you are satisfied with your responses, click the SUBMIT button.

I received no help from anyone on this assignment.