Rollerblades and ball: Observational Experiment

Aim

The aim of this experiment is to develop the idea that whether the object moves or not depends on the observer.

Prior Knowledge

Nothing.

Description of the Experiment

Eugenia skates past a chalkboard, holding a ball in her hands.

Addtional Information

Observe what happens to Eugenia and describe your observations without using the word "motion".

Observe what happens to the ball and describe your observation without using the word "Motion".

Youtube movies can be stepped frame by frame using the , and . keys on your keyboard. If you want to download the movie to your computer, right-click or control-click HERE.

Questions

• Was Eugenia moving? How do you know?



• Was the ball moving? How do you know?



• Where could the observers be, who saw Eugenia moving? Where could the observers be, who did not see that Eugenia was moving? Where could the observers be, who saw the ball moving? Where could the observers be, who do not see that the ball is moving??



• Based on your answers above, develop a precise explanation of how you can tell if something is moving or not.



• Did Eugenia observe the ball to be moving?



• According to what or whom did the ball move?



• According to whom or what did Eugenia move?



• Did the chalkboard move? If yes, according to whom? If no, justify.



• When driving in a car on the highway, who is moving: you or the trees?

Consider the phrase: "motion is relative". Use the model of motion that you have constructed to explain the meaning of this statement. Use the ideas you have developed answering the questions above.