Part B. Investigating Claims

You hear many claims made every day. Advertisers make claims about the usefulness or effectiveness of their products. Your friend may claim to be able to do something that you do not think he or she can really do. Do you believe all the claims that people make? Have you ever bought a product based on a claim made in an advertisement, only to find that the product did not work as you expected it to?

When does a claim become a fact? Scientists look for evidence to support or refute a claim. Evidence can help you determine which claims are facts and which are opinions or even misrepresentations. For example, if one of your classmates claims to be the fastest runner in the class, you could gather evidence by holding a series of races. If your classmate’s claim is true, that person should win all of the races. If another individual wins the races, your classmate’s claim was simply an opinion not supported by the evidence.

In this part of the laboratory activity, you will conduct an investigation to determine which of two opposing claims can supported with evidence. First read the section below. It describes two opposing claims. Then investigate using PASCO probeware to see which claim (if either) is supported.

Conflicting Claims About the Effect of Exercise on the Rate of Rubber Band Pulling

Student A claims that a person will be able to pull a rubber band more times in a minute if the person exercises first. Student A suggests that exercising produces a faster pulse rate, which indicates that the blood is getting to the muscles faster.

Student B claims that a person will be able to pull a rubber band more times in a minute if the person does not exercise first. Student B suggests that exercise takes energy away from the muscles, and a person who has been resting will have more energy.

Which of the two students do you agree with? ______How could you find out for sure which claim is correct?

______

Name:

Group:

Group File name:

Student Worksheet

  1. Discuss and assign each of the following roles:

Athlete – exercise for the specified amount of time

Name: ______

Task manager- assure all aspects of the experiment are being executed properly and in a timely fashion. Count the number of peaks above 20 N.

Name:______

Software Specialist –create a graph of the Force vs. Time for 1 minute as the athlete is pulling on the rubber band for 1 minute. Count the number of peaks above 20 N to compare to the Task Manager count, average both counts and fill in the space provided.

Name: ______

  1. Open your assigned Numbers worksheet and fill in the information on the top bar.
  1. Take your heart rate for 30 seconds, record below:

Heart rate for 30 seconds:______

  1. The Athlete of your group will take their digital heart rate.
  1. Plug the PASCO heart rate monitor into the PASPORT and then into the computer.
  1. Attach the heart rate monitor to the right ear of the volunteer.
  1. Working in your group, the Software Specialist will start recording the heart rate of the Athlete by clicking the START button on the computer.
  1. Click and drag “run 1” to the graph section and record the data for 30 seconds (Click STOP at 30 second mark). Record the digital heart rate below:

Digital Heart rate: ______

  1. Compare the heart rate from steps 2 and 7. Are the results the same? If not please give some possible explanations below:
  1. Discuss the 2 scenarios provided to you within your group. You will have 5 minutes to interact with your group and select the scenario that you agree with. Following your discussion fill in the following items on your worksheet: Questions, Hypothesis, Materials/Apparatus, and Procedure.
  1. Calculate the resting heart rate of the Athlete using the PASCO probeware for 1 minute. NOTE: This will be done with the teacher using the projector
  1. Each group is assigned a time interval in order to conduct the experiment.
  1. The athlete of each group will do jumping jacks for the time interval assigned to their group (ranging from 0-90 seconds). Following the jumping jacks the roles are as follows:
  2. Athlete – exercise for specified amount of time, then be seated and place heart rate monitor on right ear. This will confirm a 30 bpm rate over resting rate. NOTE: EXERCISE must result in a heart rate that is over 30 bpm of their average resting heart rate or the athlete must exercise again. Then s/he will pull on a force sensor with a doubled up rubber band, using only two fingers to pull band for 1 minute. The sensor must be kept stationary while recording. Use your other hand to hold it flat on the table.
  3. Task Manager – assure all aspects of experiment are being executed properly and in a timely fashion
  4. Software Specialist – Create a graph of the Force versus time for 1 minute as the athlete is pulling on the rubber band for one minute.
  1. Task Manager and Software Specialist will count the number of peaks on the graph that exceed 20 Newtons for each of the 3 experiments conducted. Athlete will rest for 1 minute.
  1. Repeat this experiment 3 times.
  1. Add the number of peaks below 20 Newtons for each experimental run. Hold a piece of paper at the 20 N line and count peaks below it (if PULL FORCE IS NEGATIVE).
  1. Enter each result in the provided Numbers worksheet and in the column that is colored. The average will be calculated by program.
  1. When your group is done report the results to the teacher. A graph will be generated by the worksheet. Make sure you have completed the worksheet including Questions, Hypothesis, Materials/Apparatus, and Procedure.
  1. Enter the class results in the remaining columns (NOT COLORED).
  1. Answer the following Questions and turn in with your final lab report:
  1. What did you learn?
  1. What does this result say about: Conclusion, Suggestions for Improvement, Suggestions for future research.