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(Apparent Weightlessness) Activity

In order to feel weight there must be a "reaction" force.

If you jump out of a window, you would feel weightless because there is no reaction force pushing up on your feet.
[This activity accompanies the previous section's demonstration.]

Note: Weight is defined as the pull of gravity. If you are floating about inside the space station while orbiting the Earth, it would be tempting to say you are weighless -because of your floating. But the Earth's gravity is still pulling on you (or else the station would shoot off into outerspace.) If the Earth's gravity is still pulling on you and this defines weight, then you are not weightless. It is apparent weighlessness.

FREE FALL (Apparent Weightlessness): ACTIVITY

Materials: cup (with holes), water, chair, paper towels, trash can

Poke two holes on opposite sides of the bottom of the cup. Stand in a chair. Hold the cup with your fingers over the holes. Fill the cup 1/3 full with water. Hold the cup with your other hand. Briefly remove your fingers from the holes. Observe what happens. Cover the holes again with your fingers. Hold the cup up as high as possible. Drop the cup and observe what happens to the water this time.

Why doesn't the water come out of the holes when it is dropped?

When on the roller coaster below do you think you feel weightless?

The use of phase "apparent weightlessness" is because the in freefall the rider does not feel the ractio force of the chair on his or her bottom. This gives the sensation of weightlessness. He or she does not feel hte reaction force of the seat because the rider is moving vertically at 9.80 m/s2 and so is the roller coaster car. Weight is defined as your mass times the acceleration of gravity. As you fall, gravity is accelerating you down at 9.80 m/s2 -it is not zero.

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