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New Unit:

In this unit you will:
1. Describe an objects position by locating it relative to another object or the background.
2. Describe an objects motion by tracing and measuring its position over time.
3. Identify contact/noncontact forces that affect motion of an object (e.g., gravity, magnetism, collision).
4. Predict the changes when an object experiences a force (e.g., a push or pull, weight, friction).
5. Explore how machines can make movement easier.

Marble Mystery

Today's Experiment

If the bottles were filled with water instead of rice, you would see the water level rise in the bottles when the chopsticks were plunged into the water. The water would have no difficulty creeping up the neck of the bottle to make room for the chopstick. The rice, however, is not a fluid like water and has great difficulty moving up the neck of the bottle. Instead, the packed rice has very little room to move so it tends to press against the sides of the bottle.

The scientific principle that makes this feat work is friction. The chopstick gets wedged between the rice and the sides of the bottle. That’s all there is to it. Friction is the magician.