Force and Motion

During science, we have been learning about forces and how they effect objects. The students have learned about speed and how it is measured. And they have learned about gravity and weight. Finally, we explored friction and how it effects moving objects. 

We concluded our unit by conducting an experiment about friction. 

Our Mission and Essential Questions:
           Determine which material causes the most friction, 
           Determine which material causes the least friction.
This experiment meets the requirements of the 2016 MA Science Standard 2-PS3-1 (MA). Design and conduct an experiment to show the effects of fiction on the relative temperature and speed of objects that rub against each other.

The "Set Up":
I introduced the students to the "set up" of the experiment including several fixed variables. I used 2 dictionaries to prop up a cardboard ramp. I used masking tape to hold the ramp and meter sticks in place. I explained that these items need to stay exactly the same each time we had a trial, which would be letting a car roll down the ramp. The students figured out that the car was also a fixed variable because if we used different cars that might alter our results. 
Then, I introduced the students to the different friction-causing materials, the variable. these materials were to be laid in position at the bottom of the ramp. They included coarse sandpaper, fine sandpaper, terrycloth towel, and non-slip shelf liner. The fifth variable was the rug alone.

                                     

Hypotheses:
Next, each student made a prediction of which material will create the most and least friction. They recorded them on this chart. 

                                        

Trials:
We conducted 3 trials for each friction-causing material and recorded them on this chart. We then found the median distance rolled by eliminating the highest and lowest for each material. We compared the median distances.

                             

The Results:
The material that caused the most friction, thus slowing the car to roll the shortest distance, was the rubbery shelf liner!
The material that caused the least friction, thus allowing the car to roll farthest distance, was the rug!
                              

                                

Recording our observations:                  
Students then discussed the findings. After that, they recorded their observations during the experiment, as well as, their thoughts about their own predictions and the results.