Physics Connections

Title: How Long Do I Have To Hold My Breath?

Background: Asthma is an increasingly common breathing disorder among students. Some people minimize its risks but not being able to inhale enough air is a panicky situation. And, maybe each of us has heard of someone dying from complications relating to asthma.

Although air pollution has not been positively identified as the cause of asthma, it is suspected of being a "trigger" setting off attacks in people who already have the condition. If asthmatics know bad air is on the way, they are able to plan their activities to minimize exposure to it and reduce the chance of an asthma attack. A "bad air" warning system might provide data about the speed and direction of the approaching air mass.

Process: Answer the following questions.

Questions.

1. a) The following data describe the motion of a mass of polluted air. Name the two types of data values. b) The data contains how many ordered pairs?

c) How do we know which values to plot on the abscissa (x axis) and which on the ordinate (y axis)?

d) There are how many x coordinates in the data?

e) How many y coordinates?

Data

time (days): 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

distance (km): 16 30 45 67 79 101 110 126 144 162 176 194 205 221 238 257

2. a) State the domain and range of the data.

b) How does knowing the domain and range help you choose the proper scale for the graph's two axes?

c) State the scale you have chosen for each axis.

3. a) Are there any negative coordinates in this data set?

b) So, which quadrant will we use to plot the graph?

c) Now, plot the graph.

4. a) Find the slope of the graph.

b) What does the slope tell us about the motion of the air mass?

5. a) Find the equation for the plot.

b) What is the purpose of finding the equation of the plot?

6. How could this data about the motion of the air mass have been collected?

7. a) If you received some new data about the movement of the air mass, how could you tell if it fit into

the existing pattern of motion?

b) Do the following data fit the existing pattern?

4.5 days, 80 km 6.2 days, 105 km 10.7 days, 170 km 13.2 days, 250 km

8. a) How can the graph predict when the air mass will reach us if we are located 600 km from its source?

b) If the air travelled for 20 days, how far might we expect it to move?

9. What are some types of industries suspected of releasing "bad" air?