Grade 10 Science Unit 4 Weather

Grade 10 Applied Science – Climate Change

Movement of Energy – Convection Currents

Life on Earth is sustained by energy. Energy “moves” by four processes: (1) radiation, (2) conduction, (3) advection and (4) convection. In convection, a vertical current movement of energy is established dependent on temperature. With respect to air, warmer air expands (i.e., molecules separate), becomes less dense and lighter, and moves upward. Cooler air behaves oppositely. The cooler air contracts, becomes more dense and heavier, and moves downward. A similar convection current forms in water.

How does the temperature of water affect water movement?

Materials

·  Water

·  Bag of ice cubes

·  Food colouring

·  Plastic bin / Clear fish tank

·  Beaker

·  Kettle / Warming Pad

·  Stop watch

·  Tape measure / Ruler

Procedure - Methods

1.  Place the beaker in one corner of the plastic bin

2.  Fill the plastic bin with cold tap water so that the water is below the top of the beaker

3.  Fill the beaker with boiling water

4.  Place the bag of ice cubes in the OPPOSITE CORNER of the plastic bin (i.e., away from the beaker)

5.  Drop a few drops of food colouring near the beaker

6.  Make observations including variables such as direction, distance, time and speed

Prediction - Hypothesis (Read the procedure AND make your prediction before conducting the experiment)

Observations - Results (sketch, data, verbal description)

Discussion – Relate your results to your scientific thinking AND researched facts (e.g., reference your textbook, Internet).

Conclusion