Try This At Home: Scientific Method with Pendulums

Scientific Method – Pendulums

Now that you’ve listened to our podcast, you probably have a different view of how the parts of the scientific method fit together. Circle the picture below the best represents the order and direction steps of the scientific method fit together.

To practice thinking about how this plays out in real life we are going to consider pendulums. If you wanted to discover properties of pendulums depending on the weight and length of the string, what are ways you could start at three different  parts of the scientific method. Write them down

Did you start by asking a question? By designing an experiment? By doing background research? By coming up with a hypothesis? By observing some pendulums and collecting preliminary data? 

All of these are reasonable places to start. Try it.

Make a flow chart for each of these starting points for  the scientific method.  

1. Start with the following question and plan a way through the scientific method: How does the length of the string and the weight affect the number of swings of a pendulum?
2. Start with some observations about pendulums and plan a way to test how the length of the string and the weight affect the number of swings.
3. Start with background research and develop a hypothesis for how the length of the string and the weight affect the number of swings.

Did you notice similarities and differences in how you get started? Will you end up with the same conclusions? Is one starting point inherently better than the others? Why or why not?

Design your experiment.

Now that you have come at the problem from different directions it is time to design a good experiment. Your challenge is to come up with a hypothesis and a procedure to use to test your hypothesis using the following materials: string, ruler, tape, timer, washers or paperclips to use as weights.

Here are some questions that will help guide you in your design.

1. What variables will you be recording for your experiment? Which ones are independent (manipulated) variable(s) and which are the dependent (responding) variable(s)?
2. You are working with a couple of different variables, when developing your hypothesis do you want to have a separate hypothesis for each variable or combine them?
3. How will you measure the number of swings?
4. Will you test each variable more than once.
5. How can you ensure that each test is the same? How will you drop the pendulum? How will you secure the pendulum? Do you think holding the pendulum string with your hand will work well?
6. How will you share your conclusions with others?

Did you come up with any new questions to test?

Frequently, scientists will start by testing on thing and then get curious about another aspect of the thing they were studying. This helps them keep discovering more about the world. What new questions or observations occurred to you while doing your experiment?