Read the investigation and write a conclusion for the investigation.

Tracey and Brendan wondered about the effect of different types of milk on the swirling motion in the famous “Milk Co-Motion” experiment. They did the following investigation.

Question:  What effect does using skim milk instead of whole milk have on the milk co-motion experiment?

Prediction (hypothesis):

If we put skim milk in one Petri dish and whole milk in the second Petri dish, then the milk in the Petri dish containing whole milk will swirl longer than the milk in the Petri dish with Skim milk after we put Dawn detergent in the middle of the milk, because there is more fat in the whole milk and the swirling is caused by the reaction of the fat and the detergent. 

Materials:

40 ml whole milk

40 ml skim milk

two Petri dish bottoms

food coloring (4 colors)    

Dawn detergent

stopwatch

Procedure:

1.      Gather materials

2.      Pour the skim milk in one clean Petri dish and the whole milk in the other.

3.      Put four drops of food coloring in the milk near the edge of each Petri dish

4.      Drop one drop of detergent in the middle of each Petri dish

5.      Start the stop watch and time the swirling of the milk in each Petri dish

6.      Record the length of time that the swirling continues

7.      Repeat the investigation (steps 2-6) for Trials 2 and 3.

8.      Calculate and record the average for the trials. 

9.  Clean up materials and wash hands.

Results/Data:

       Summary:  The whole milk resulted in a longer "swirling time" than the skim milk.

Write a conclusion for Tracey and Brendan’s investigation.

In your conclusion, be sure to:

·        Answer the investigative question

·        State whether your hypothesis is supported or not.

·        Include supporting data from your data table (Use numbers! Include highest and lowest examples and averages.)

·        Explain how these data support your conclusion