Unit 13 Contents

Planning the Experiment

Shannon used the sandwich she brought for lunch to do an experiment. She placed her sandwich on a two-pan balance and used standard masses to find its mass. Then she took a bite out of her sandwich and found the mass of the remaining sandwich. Shannon kept taking bites out of her sandwich, each time finding the mass, until her sandwich was gone. She recorded her data in a table like the one below.

You will repeat Shannon's experiment using a sandwich of your own.

1. What are the two main variables in the experiment?
1. Which of the two main variables is the manipulated variable? Justify your answer.
2. Which is the responding variable? Justify your answer.
3. What letters will you use to stand for the two main variables?
3. Shannon wants to look for patterns in the data to help her make predictions about the number of bites and the mass of the sandwich. What important variables should she keep fixed?

Draw a picture of the experiment. Be sure to identify the variables in your picture. Label the main variables with letters.