Inquiry Skills Used

This is a research activity using primary and secondary reference sources to ask questions, make assumptions, and draw conclusions.

Safety Considerations

Never allow children to look directly at the sun to determine its location! Use care when working with the saw, hammer, and nails while making the stand. Mercury thermometers should NOT be used.

Background

When students use small cut-out models to check for changes in the length of a shadow, they often find little change from hour to hour. So, why not ‘super size’ the model to make the changes more obvious? Including a thermometer on the cardboard cut-out allows for the identification of a temperature change as well as relating temperature change to the length of the shadow and the position of the sun.

What You Need

Hammer

Nails

Saw

Wood (2x4)

Cardboard

Pencil

Thermometer

Chalk

Paper

Measuring tape

Safety goggles

What to Do

  1. Have someone tall (preferably a good-natured administrator) lie on the cardboard.
  2. Draw or chalk around the person and cut out their shape.
  3. Use the saw, hammer, nails, and wood to fashion a stand for the cardboard cut-out.
  4. Attach the thermometer onto the cut-out.
  5. Attach the cut-out to the stand and put it outdoors facing the morning sun on a bright, sunny, cloudless, windless day. A hazy day could affect the sharpness of the shadow’s 'edges'. As an alternative to building a stand, you could attach the cut-out to a broom handle and prop it up in the sand box. The chalk outline could be traced in the sand with a stick and stone markers could also be used.
  6. Every hour, go outside and draw around the shadow with different coloured chalk.
  7. Record the length of the shadow as well as the temperature. Unless there is a cold front moving in, the temperature should increase as the day progresses. The students will be surprised that the temperature does not immediately drop at noon, which may lead to further researching of land temperature.

Where to Go from Here?

Students could investigate the properties of opaque, translucent, and transparent materials. Setting up an indoor simulation using a flashlight will provide a safe context for students making the connection between the location of a shadow and the position of the sun.

STSE Links

What common device in the past made use of this knowledge?

What kind of jobs would still need to know this type of information today?

When building tall buildings, how can the architect build structures beside each other and still maximize the amount of light entering the windows from the sun?

Cross Curricular Connections

Language

  • Students can write a story about their shadow and how it grows and shrinks each day.
  • For media text, the student can describe how shadows are used in media to represent sinister characteristics.

Mathematics

  • Recording the temperature – thiscan be used for graphing.
  • Measuring the shadow length – measurement, and also graphing, particularly a line plot.

Art

  • The students can begin to introduce shadows to their art work. They should know that all shadows fall in the same direction in the picture.

Credit Where Credit is Due

Adapted from Discovering Science--Heat, Light and Sound, a Frank Schaffer Publication.