Lesson Plans: Moving Water and Waves
Objective
The objective of this activity is to enable students to demonstrate how wind causes water to move and generate waves and how water pressure causes water to move from higher to lower pressure.
Materials
Each student or group of students will need the following:
- A rectangular metal or glass container
- Water
- Approximately 2 kilograms of sand (optional)
- Electric fan or a hair dryer
- Stopwatch or watch with a second hand
Important Points to Understand
Everyday we see masses of water always on the move. Although there may be very little observable movements on the ocean surface on a very fine day, in fact, the ocean water is always moving. There are many ways that you can make waves in water. Most waves are created by winds.
Procedure
- With sand, construct a beach at one end of the tank.
- Fill the tank with water to a depth of about 5 centimeters.
- 3) Place the fan or hair dryer on one side of the container so that the fan can blow onto the surface of the water. It should be aimed down the tank along the surface of the water at about a 45-degree angle.
- Switch on the fan (or hair dryer) at a lower speed then at a higher speed. Allow 2 minutes for each trial. Let the students observe the different results.
Questions
- What happened when the fan (or hair dryer) was switched on?
- What happened to the waves when the fan (or hair dryer) was changed to a higher speed?
- What happened to the size of the waves as time progressed?
- Did you notice any differences in the waves from one end of the tank to the other? If so, what were they?
- While the fan was running which side of the water tank had the higher pressure of water?
- What happened when the fan was switched off?
- From all your observations, what characteristics of winds are important in determining the height of a wave?
