Shadow Length and Direction Lab

Washington, DC — Latitude 38.9° N

Investigation

Observe how the length and direction of a flagpole’s shadow change during the day and across three important seasonal dates. The flagpole is 3 meters tall.

  1. Select a season and a time, sunrise, or sunset.
  2. Observe the shadow from overhead and the Sun’s height from the side.
  3. Record the data.
  4. Look for patterns in shadow length and direction.
1. Choose a seasonal date
2. Choose a time
Season Equinox
Time 12:00 PM
Shadow Length —
Shadow Direction —

Overhead View

The compass shows the direction the shadow points. The yellow marker shows the Sun’s direction.

Side View

Think: Why are shadows usually shorter when the Sun appears higher in the sky?

Observation Table

Season Time Sun Above Horizon? Sun Altitude Shadow Length Shadow Direction
Analyze: During which time is the shadow shortest? How does the noon shadow change from summer to winter?

This model uses Washington, DC latitude and simplified solar geometry. Times are treated as local solar time so that solar noon occurs at 12:00 PM. Actual clock times vary slightly because of longitude, daylight saving time, and the equation of time.