Experiment 7 Work

Course

Please type your name:

Please type your LAST NAME and LAST FOUR SS# digits:

IN:

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.

A weight lifter picks up a barbell and
  1. lifts it chest high
  2. holds it for 5 minutes
  3. puts it down (but does not drop it)
Rank the amounts of work W the weight lifter performs during these three operations. Label the quantities as W1, W2, and W3. Justify your ranking order.

2.

Estimate the amount of work performed on a 1200 kg car as it accelerates at 1.2 m/s² over a 150 meter distance.

3.

A tiny rocket engine accelerates a toy car over a distance of twelve meters. The thrust of the engine vs. the distance is shown on the graph. Which of these is the best estimate of the work performed by the little engine? (Note: Each division on the graph represents one unit --- one meter on the x axis and one newton on the y axis.)

114 J

75 J

46 J

Less than 1 J

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.