Thursday, May 4, 2017

SCIENCE WEEK 2017, St. Agatha School: Torque

I did this lesson with three 3rd grade classes.  In retrospect, I decided that in the future I would leave out centripetal force and angular momentum, as Science Week classes are short with no follow-up by me.  It would be better to introduce those two forces in separate classes.  Or wait to teach them to kids in higher elementary grades.


Who jump ropes, hula hoops, or dances? Is that science? Why? Why not?

a globe; chalk or markers / I'll bring ropes, hoops, leaflets, activity sheets

A. Introduce new vocabulary:
axis of rotation – torque – centripetal force – angular momentum

  1. Have someone do a demonstration on the hula hoop.
    Notice it turn in a circle
    * Show the globe: turns on its axis of rotation                      Pronounce
    * You are the axis of rotation, too, when you hula hoop.
  2. Have someone do a demonstration of jump roping.
    * See it also turn on its axis of rotation.
    * This turning force is called torque.                                    Pronounce
  3. When the force heads to the center and seeks it out
    (like Hide & Seek), it is called centripetal force.                 Pronounce
  4. Have you heard of momentum? What do you think it means?
    * When you're running at a slow speed, you can stop quickly -- because you have less momentum.
    * When you're running at a fast speed, it takes longer to stop -- because you have more momentum.
    * With momentum, we usually think of moving in a straight line, but you can run around in a circle, too.
    * What does a circle have lots of? Angles. (Illustrate on board.)
    * Called angular momentum (like a revolving door).            Pronounce
B. Free play, hoops and ropes Ask individuals to explain the terms.                 Play The Twist.   You rotate back and forth (like a washing machine).

Pass out the art activity sheet, and draw a cartoon of one of these activities.


Leaflets*. Tell your friend, family, anyone you want about what you learned today.

*  The leaflets for hula hooping and jump roping can be found elsewhere in this blog.


Called “Twists and Turns”

axis of rotation         centripetal force

angular momentum                              torque
YOU are the cartoonist!
  1. At the bottom of the page, draw a picture of you and someone you know hula hooping --- or jump roping --- or dancing The Twist.
  2. Now you have the beginning of a cartoon.
    Put what you say in a balloon like this:                                                                                                        NOTE:   On the printout:
                                                        Draw a simple cartoon here  
  1. Then use one of the science terms in the box above to tell your friend about the science. Write the conversation in the balloons.
Twists and Turns                                     by                                                 

Kathy Dullea Hogan
Gateway to Science: Sports and Games