Water Beats Rock

This science fair project highlights weathering, the breaking down of rock, by moving water. Students might find it hard to believe that something as simple as water is capable of breaking down such a durable material as rock. By doing it themselves they’ll see just how easy it is!

Outlined in this project is the purpose and hypothesis to help clarify the point of the project. The approximate duration, a short materials list, and an easy to follow procedure is also included. Finally, questions to ask along the way and upon completion of the project are provided.

Purpose: To observe the effect of moving water on “rock”.

Question: Will still or moving water weather a rock faster?

Hypothesis: If a rock is placed in moving water then it will break down, or weather, faster.

Statement: Moving water weathers rocks faster.

Estimated Duration: 15 minutes

Materials List:

  • chalk – the rock
  • 2 clear cups
  • water
  • 1 permanent marker
  • paper and pencil

Procedure Outline:

  1. Mark one cup “Moving”.
  2. Fill each cup halfway with water.
  3. Break one whole piece of chalk in half.
  4. Put a piece of the chalk into each cup.
  5. Pick up the cup marked “Moving” and shake and swirl it, be careful not to spill, for 2 minutes.
  6. Record your observations of both cups.
  7. Pick up the cup marked “Moving” and shake and swirl it again for 2 more minutes.
  8. Record your observations of both cups.

Be on the lookout for…
What happened to the chalk in the Moving cup?
Did anything happen to the chalk in the other cup?
When the water settled down in the Moving cup, did you notice anything at the bottom of the cup?
What do you think would happen if you continued to swirl the Moving cup?
Do you think rocks would weather, or break down, faster in a river or a pond?