Weights and Lengths

Credit: Ms. Debra Amo, Heuvelton Central School

Description

In this experiment, students will examine whether the weight of an object is a linear function of the distance of the object from the scale.

Data Collection

Working in groups, students place one end of a plank on a bathroom scale and the other end of the plank on a brick or piece of wood about the same height as the scale.
  1. One student stands on the plank while another student records the distance to the scale end of the plank and the weight shown.
  2. A second set of data using a plank of a different length will also be collected in the same manner as the first.

Use of graphing calculator

Students will create scatter plots on the graphing calculator (and also on the computer using a spreadsheet) of the distance versus weight of the object. They will then use the linear regression function to find the line of best fit.

Interpreting the Data

IN REPORT FORM, students will use the information from the linear regression to decide if the data shows a linear relationship. Students will also use their equation or graph to extrapolate and interpolate information from their data as well as discuss the meaning of the model and the significance of both its x and y intercepts.

Personal Experiment

ON THEIR OWN, students should design a similar experiment in which they hypothesize that the relationship will be linear. A similar experiment does not have to measure weight. The student could concentrate on volume or length (as in the length of a spring) for example. Likewise it does not necessarily have to relate to the distance of an object from a certain point. Try other modifications to an object (or objects) besides distance.

PROJECTS WILL INCLUDE BUT ARE NOT LIMITED TO:
  1. Graphs of the data from the group experiment as well as the personal experiment.
  2. Hypotheses for both the group experiment and the personal experiment.
  3. A discussion for the experiments explaining if the data were linear and what led you to this conclusion.
  4. A discussion for both experiments explaining the overall meaning of the model (graph) and the significance of the x and y intercepts.
  5. An interpolation (find a value between two data points) and an extrapolation (finding a value outside of the measured data) for both experiments.

YOUR REPORT: Organize the report using an experiment format: (Use the following underlined titles as headings in your report.)

Investigation question: What are you investigating? Be specific: address both the class experiment and your personal experiment.

Hypothesis: What was your guess to answer your question (s) before you did your experiment?

Method: Description of how your experiment was done.

Data: Organized in tables and scatter plots.

Data Analysis: This is where you get to interpret the different pieces of information that you have. You may add any additional comparisons that you feel are important or interesting.

Conclusions: How do your results compare to your hypotheses? Are the results what you had expected? Why do you think this occurred? What did you learn?

>Be sure to review the rubric. How does your project measure up?