Dynamics Introductory Activity

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This activity is designed to reveal your preconceptions about the causes of motion.


Discuss the following situations with the other members of your group. Try to come up with specific and complete answers. ("Gravity", for instance, is not a complete answer.) Each individual in the group should record their own answer.

  1. Situation: A book is lying at rest on a table. Why? In other words, what causes the book (or any object) to remain at rest?

  2. Situation: The Voyager spacecraft is moving out of the Solar System in a straight line with constant speed. Why is it doing that? What causes an object to move with constant velocity?

  3. Situation: A pencil rolls off the desk and falls to the floor. Why does it move the way it does? We know a lot about this motion (free fall) - but what causes it to happen? Why do objects accelerate?

  4. Situation: A book sliding across a table gradually comes to a stop. Why? What causes a moving object to gradually come to a stop?


last update March 1, 1999 by JL Stanbrough (jerry_stanbrough@bhs.batesville.k12.in.us)