Shadows Lesson

Have you ever made shadow puppets? If you put your hand between a flashlight and a wall, you will make a shadow like the image shown. Light travels in a straight line from the flashlight, but your hand blocks the light from reaching the wall. This creates the image on the wall.

How is the shadow produced?

• Light travels in a straight line.

• Light is blocked.

The Sun shines on Earth like a giant flashlight. Light from the Sun causes shadows that we can see here on Earth. Shadows are formed when an object blocks light. For example, when sunlight hits the metal piece on this sundial in the picture, it forms a shadow. The shadow can be used to tell the time of day. What does a sundial do?

• A sundial uses shadows to tell time.

• Turns off the Sun.

• Turns off the Moon.

Shadows change shape and direction during the day. Shadows are opposite the light source. When the Sun first rises in the east (sunrise), it sits very low on the horizon (edge of the land). The sunlight hits an object at an angle that creates long shadows from the object. The shadow will get smaller as the morning passes. In the middle of the day (at 12:00pm), the Sun sits directly above us in the sky. This creates little to no shadow. As the Sun nears the west horizon (sunset), it creates longer shadows again.

Look at the image. At 7:00 am, the shadow is _________compared to noon.

• longer

• shorter

• non-existent

The Sun always rises in the East (sunrise) and sets in the West (sunset). This movement across the sky directly affects shadows in two ways: size and direction. Shadows are opposite the light source, so when the sun rises in the East, shadows point west. By evening, when the sun is setting in the West, shadows are pointing East. When the sun is low (morning and evening), shadows are long and stretched out. When the sun is high (midday), shadows are short.

Look at the diagram of the shadows baed on the pole. Which is the best description for the shadows occurring from noon to 3:00pm?

• The shadows are getting shorter before sunrise.

• The shadows are getting longer before sunset.

Tags

NGSS.MS-ESS1-1

Practice Question (PQ): A student placed a stick in the ground and then recorded the position of its shadow at different times of the day as the Earth turned and the sun moved across the sky.

Which outline in the student's recorded observations (see image) represents the positions of the stick's shadow at 10:00am?

• A

• B

• C

• D

Tags

NGSS.MS-ESS1-1

What time of day do you think it is in this picture?

• 8:00 am

• 10:00 am

• 12:00 pm (noon)

• 2:00 pm

What time of day do you think it is in the picture?

• 8:00 am

• 12:00 pm (noon)

• 5:00 pm

• Either 8:00 am or 5:00 pm