YOUR AVERAGE SPEED LAB

Science Standards: a. Positions is defined to some choice of standard reference point and a set of reference directions. b. Students know that average speed is the total distance traveled divided by the total time elapsed and that the speed of an object along the path traveled can vary. c. Students know how to solve problems involving distance, time, and average speed. f. Students know how to interpret graphs of position versus time and graphs of speed versus time for motion in a single direction.

Problem: What is the average speed of a student’s journey?

Materials: chalk, stopwatch, markers(dominos), 2 meter sticks/measuring tape

Procedure:

Walking foot to foot

  1. Mark a line with chalk on the ground. This is your reference point for starting.
  2. Have a stopwatch in hand. In your other hand carry 6 domino markers.
  3. Start the stopwatch and walk for 5 seconds in a straight line. When the timer says 5 seconds drop a domino on the ground. KEEP WALKING, do not stop.
  4. Every 5 seconds drop another domino marker on the ground, until all the dominos are done.
  5. Measure the distance in METERS from the original reference point to see how far you walked for each 5 second time increment. Record the time in your table. (39.4 inches = 1 meter)
  6. Repeat steps 1-5 with your lab partner.

Steady Walk

  1. Now repeat steps 1-6, but this time walk at a steady pace. Record your data in the data table.

Vary your trip

  1. Now this time you will repeat steps 1-6 but you will walk fast, slow, walk back the way you came, walk slow and perhaps walk faster again. You can even stop completely for 5 sec. Try to vary your trip, where you walk and how fast you walk.
  2. Calculate average speed using Average speed = total distance/ total time or V=d/t Record in your data table. Include correct units and significant figures.
  3. Graph your trip. Give you and your lab partner a different color for each line of your line graph to show your motion.

Data:

Time in seconds (s) / Distance in meters (m) 39.4 inches = 1 meter
Walking very slow constant pace / Walking slow constant pace / Varied Trip(slow, fast, stop, walk back)
Name: / Name: / Name: / Name: / Name: / Name:
0
5
10
15
20
25
30
Average speed
m/s
Color of line on graph

Questions:.

  1. Using your data, make a line graph showing distance on the dependent variable axis and time on the independent variable axis. Refer to your book for examples of motion graphs. Follow all rules for graphing. Include a key to show the data for each trial and the average.
  2. Is your speed constant over the entire time? Use information from your graph to support your answer.
  3. World record holder Usain Bolt runs the 100m in 9.58 sec and the 200 m in 19.19 sec. What is his speed in each event? What is his speed in mi/hr? (Hint: multiple your answers by 2.2).
  4. Major league pitcher Nolan Ryan was officially clocked throwing a fastball 100.9 mi/hr. How fast is this in m/s?

Conclusion: