Hot and Cold Water

Essential Question
How does temperature affect density?

Objectives

 * Explain why there are different layers of water (indicated by the food coloring).

Introduction & Student Background
TBW

Materials

 * Clear plastic box (shoe box size)
 * 3 ounce paper cups
 * Clothespins
 * Water
 * Ice
 * Food coloring
 * Water boiler
 * Water Pitcher
 * thermos

PREP

 * 1) Heat the water in the boiler until it is hot (does not need to be boiling). Put the hot water into a thermos. This is to prevent burns.
 * 2) Put blue food coloring in the pitcher of ice water and red food coloring in the thermos with hot water.
 * 3) Attach the paper cups to the edge of the plastic shoebox with clothespins. The bottom of the paper cup should be just at or under the surface of the water in the shoebox. The water in the shoebox should be at room temperature, hotter than the ice water and colder than the hot water.
 * 4) Minimize turbulent motions in the water by letting it sit for a while.

ACTIVITY

 * 1) Put the red hot water in one paper cup.
 * 2) Puncture a small hole in the bottom of the cup. The red liquid will run out into the water in the shoebox.
 * 3) Do steps 1-2 for the blue cold water.

How it Fits to Standard

 * Answer questions by explaining observations of the natural world

Follow Up
What do the positions of the different colored water in the shoebox tell you about the relative densities?