Shadows Over a Day: Shadow Sticks and Sundials — Answers
Answer sheet with model answers and success criteria for the 3rd Grade the solar system & space worksheet.
Success TutoringWorksheetsAnswer sheet3rd Grade · Science · The Solar System & SpaceShadows Over a Day: Shadow Sticks and Sundials — Answers
Part A: Why shadows change
Read the passage. Then circle the best answer.
A shadow forms when an object blocks sunlight. The shadow always falls on the side of the object away from the Sun.
The Earth spins on its axis once every 24 hours. As it spins, the Sun seems to rise in the east, travel across the sky and set in the west. The Sun is not really moving across our sky — we are turning.
When the Sun is low in the sky, in the early morning and late afternoon, shadows are long. When the Sun is high, around the middle of the day, shadows are short.
Because shadows change in a regular way, people long ago used them to tell the time with a sundial.
- Atowards the Sun
- Baway from the Sun
- Cstraight up
- Dat the Moon
Answer: away from the Sun
The object blocks sunlight, so the shadow falls on the side away from the Sun.
- AThe Sun goes around the Earth each day.
- BClouds push the Sun along.
- CThe Earth spins on its axis.
- DThe Sun gets bigger and smaller.
Answer: The Earth spins on its axis.
The Earth turns once each day. As we turn, the Sun seems to rise, cross the sky and set.
- Aearly morning
- Blate afternoon
- Cjust before sunset
- Daround the middle of the day
Answer: around the middle of the day
Around the middle of the day the Sun is highest in the sky, so shadows are shortest.
- Awest
- Beast
- Cup
- Ddown
Answer: west
Shadows point away from the Sun. With the Sun in the east, shadows point west.
Part B: Fill the gaps
Answer: long
Answer: 24
Answer: blocks
Also accept: stops.
Answer: East — away from the Sun.
Part C: True or false?
Write True or False.
Answer: False
Shadows change length as the Sun's position in the sky changes.
Answer: True
As the Sun seems to move from east to west, the shadow swings around the object.
Answer: False
The Earth spins on its axis. That is what makes the Sun seem to move.
Answer: True
The shadow of a pointer falls on different marks as the day goes on.
Part D: Working scientifically: a shadow stick
Use Leo's results to answer. Never look straight at the Sun.
Leo pushed a 30 cm stick into the ground in an open, sunny spot. Every two hours he measured the length of its shadow.
8 am: 70 cm · 10 am: 35 cm · 12 pm: 20 cm · 2 pm: 30 cm · 4 pm: 65 cm
Answer: 12 pm (midday) — 20 cm.
Answer: 8 am — 70 cm.
Answer: 35 cm (70 − 35 = 35).
Model answer: The shadow was long in the morning, got shorter until midday, then got longer again in the afternoon. This happens because the Earth spins: the Sun is low in the morning, highest around midday and low again in the afternoon. A low Sun makes a long shadow and a high Sun makes a short shadow.
Success criteria:
- Describes long – short – long
- Links shadow length to how high the Sun is
- Explains the Sun's apparent movement by the Earth spinning
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.
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