Unit 2 Worksheet 3

1.         Robin, roller skating down a marked sidewalk, was observed to be at the following positions at the times listed below:

a.         On the grid above, plot a position vs. time graph for the skater.

b.         How far from the origin was he at t = 6s?  How do you know?

c.         Write a mathematical model to describe the curve in (a).

d.         Was his speed constant over the entire interval? How do you know?

2.         In a second trial, the timer started her watch a bit late.  The following data were obtained:

a.         On the grid above, plot the position vs. time graph for the skater.

b.         How far from the origin was he at t = 5s?  How do you know?

c.         Was his speed constant? If so, what was it?

d.         In the first trial the skater was further along at 2s than he was in the second trial. Does this mean that he was going faster?  Explain your answer.

3.         Suppose now that our skater was observed in a third trial.  The following data were obtained:

a.         On the grid above, plot the position vs. time graph for the skater.

b.         What do you think is happening during the time interval:  t = 4s to t = 6s? How do you know?

c.         What do you think is happening dring the time interval:  t = 6s to t = 12s? How do you know?

d.         Determine the skater's average speed from t = 0s to t = 12s.

e.         Determine the skater's average velocity from t = 0s to t = 12s.