Rivers and streams can carve patterns into Earth's surface. This experiment will simulate the force that water can have in an environment. Will a water travel in a straight path down a slope? Before you begin, make an educated guess about the outcome of this experiment based on your knowledge of stream patterns. This educated guess, or prediction, is your hypothesis. A hypothesis should explain these things:
A hypothesis should be brief, specific, and measurable. It must be something you can test through observation. Your experiment will prove or disprove whether your hypothesis is correct. Here is one possible hypothesis for this experiment: "A gentle flow of water across a downward sloping landscape will create a meandering stream path, while a more forceful flow will create a straighter path."
In this case, the variable you will change is the velocity of the water flow, and the variable you will measure is the resulting stream pattern. You expect the stream to meander for low flows and be straighter for higher flows.
$8 for sand and gravel.
Handle the bricks carefully to prevent injury.
Study your diagrams and the tray of sand. Which size particle of sand or gravel moved the most? As the stream flowed longer, how were the patterns affected? Did your stream begin to meander at the lower flowrate and go straighter at the higher flowrate? Write a paragraph summarizing your results and explaining them.
Source: Experiment Central. U·X·L, 2000.