OzoMeter

In this activity we aim at measuring distances (e.g. the perimeter of a plane figure) with Ozobot. This activity focuses on two main topics:

1. Calibration of a measuring instrument

2. Physical meaning of a mathematical function

Material:

OZOBOT

Graph paper

Black felt tip pen

White paper

Procedure:

STEP 1 – Calibrating OZOBOT

In this step you’ll set OZOBOT in order to have a fixed relationship between a length and the time OZOBOT takes to complete it.

1. Draw on graph paper calibrated segments of various lengths.

2. Write a code to program OZOBOT to follow line with constant speed (or use it without any code). Transfer the code on OZOBOT.

3. Measure time needed to complete the different segments, repeating the measurements various time for each length.

4. Plot the distance vs. time graph, and calculate the actual OZOBOT’s speed.

STEP 2 – Measuring a perimeter

In this step you’ll provide the length of the perimeter of a polygon, measuring the time OZOBOT takes to cover it.

1. On a sheet of white paper draw a polygon. Remember to not draw too small angles.

2. Measure the time OZOBOT takes to complete the polygon’s perimeter.

3. Using the speed calculated in step 1 to find the length of polygon’s perimeter.

Extensions:

• Draw the standard segments on white paper instead of graph paper, and measure their lengths with a ruler.

• Evaluate errors in each step.

• Use graph paper with various sensibility.

• Wich error sources can you outline in your experiment?

• Set OZOBOT with a different speed. What happens to the error?