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Help - Ideas for Making a Lesson on Universal Gravitation Interesting?

  1. Mar 27, 2014 #1
    Hi all, I'm currently a student teacher. Next week I'm going to teach a lesson on universal gravitation to grade 11 students. It's the first lesson on the topic, so it will be an introduction and not too in-depth.

    I'm struggling with ways to make it interesting. I decided to start the lesson with some crazy history about Tycho Brahe, Kepler, and Newton. I also found a couple of YouTube videos with Chris Hadfield talking about gravity.

    However, I would like to make the lesson more interactive and I can't figure out how. I am being observed that day and my instructor will not like it if I lecture the whole time. Any ideas?
  2. jcsd
  3. Mar 27, 2014 #2

    Simon Bridge

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    These are 16/17yo kids?

    1. unless you are teaching science history leave off the history and teach the science.
    2. make it practical - i.e. do an experiment... better: get the kids to design and do an experiment.

    As usual: start with prior knowledge and curriculum objectives like you were trained.

    If you need to emphasize the universal-ness of gravitation then there may be problems ... i.e. demonstrating the gravitational attraction between two pens would be hard. But if not then leave off the word "universal".
  4. Mar 27, 2014 #3
    Thanks for your input. It's definitely science history. Just a couple of interesting facts to get the students thinking.

    They already know about acceleration due to gravity and have done an experiment to find g. This unit is about universal gravitation specifically.
  5. Mar 27, 2014 #4

    Simon Bridge

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    So it is a history lesson?!

    Set the stage then - what else was going on in the times these ideas were being developed?
    Were there wars on - any major political intrigue? What were the customs then? What was at stake concerning the ideas - i.e. if someone's idea was wrong, what would happen?

    More interactive - that would either be a treasure hunt (students basically do book research) or a dramatization (students work out how to make a short historical docudrama).
  6. Mar 28, 2014 #5

    Andy Resnick

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    A few ideas:

    1) emphasize the "universal" part. Ask the students if there are any other forces that result in an acceleration that is independent of the object. Let them work/discuss that for a bit (I finish by pointing out that the only other force is centripetal, and that leads to the conceptual foundations of GR) and you could move into a discussion about rotating spacecraft habitats.

    2) Discuss the meaning of the word 'gravity' and note that the common statement 'things fall because of gravity' conceals the fact that we still have no answer to "why" gravity makes things fall or understand how gravity "works". This can be tied into historical ideas about gravity.

    3) Discuss the relationship of air, vacuum, and gravity- doesn't the atmosphere "press down on us"? Air resistance also confounds the statement that 'all objects fall at the same acceleration'- so how do we know that gravity is, in fact, 'universal'? What exactly is 'vacuum', and how do you make one?

    4) Discuss the difference between weight and mass, using scales with a lb/kg switch as a guide. What does it mean to "feel the weight of an object when we hold it"? What does 'weightlessness' mean? When is an object weightless? What is the relationship between free fall and projectile motion?
  7. Mar 28, 2014 #6

    Simon Bridge

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    That may work well for a history class if the teacher hangs on to the historical story of how these ideas were worked out and can feed those into the developing discussions.

    The other approach is to use debates - feed factions of students with conflicting historical views and have them argue them out using only information and ideas available to the people at the time?

    Or - pick a couple of important figures and have students debate a point from each of those figures' points of view.

    The main restriction on taking an interactive, student-oriented, approach is time.
    If you only have an hour or so then you may be stuck.
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