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Everyday Physics · Integrate text and table evidence to explain a pattern

Why Do Shadows Change Length During the Day?

Combine an explanation of the Sun’s apparent daily path with an illustrative shadow-length table to explain why a fixed object can cast different shadows through one day.

Suggested Grades 4–6342 core-passage words20 questionsUpdated 2026-10-01
What you’ll practiseRead prose and a data table together, identify what changes and what stays fixed, describe a numerical pattern, and connect it to the Sun’s changing apparent position.

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How a fixed vertical object can cast a long shadow when the Sun is low and a shorter shadow when the Sun is higher. Same object · changing sunlight angle LOWER SUN → LONGER SHADOW HIGHER SUN → SHORTER SHADOW Concept diagram · not to scale
A fixed object can cast different shadow lengths as the Sun’s apparent height changes; the diagram is conceptual and not to scale.

One object, many shadows

A straight stick can stay in one place while its shadow changes through the day. The stick does not need to change height; the direction of incoming sunlight changes.

NASA explains that the Sun’s apparent position in our sky changes through the day because Earth rotates. That apparent motion changes the angle at which sunlight reaches the ground.[1]

Low Sun, long shadow

When the Sun is low in the sky, light reaches the ground at a shallow angle. A vertical object then blocks light across a longer stretch of ground.

NASA visualizations show that a low Sun angle can produce very long shadows. The geometry matters: a shallower light path stretches the shadow farther from the object.[2]

Higher Sun, shorter shadow

As the Sun appears higher, the light arrives more steeply. The same object still blocks the light, but the shadow does not extend as far across the ground.

The exact time of the shortest shadow depends on location and date, so a careful explanation focuses on the pattern instead of inventing one universal clock time.[1]

Read the table as evidence

The table below is an original illustrative classroom dataset for a one-metre stick. It is not a record from a particular city or date. The stick height stays fixed while the listed time and shadow length change.

The illustrative shadow is 2.4 m at 9:00, 1.3 m at 11:00, 1.0 m at 13:00 and 1.6 m at 15:00. Those values show a down-then-up pattern.[1]

Numbers show the pattern; prose explains it

The table can show that the shadow changes, but it does not by itself explain why. The prose supplies the mechanism: Earth’s rotation changes the Sun’s apparent position and therefore the light angle.

A strong reader combines both forms of evidence instead of repeating only the numbers or only the explanation.[1]

A fair comparison keeps important things the same

The same object, location and measuring method should be used across rows. If the stick height changed, the rows would no longer isolate the effect of time and Sun position.

That is the reading skill: identify the claim, find numerical evidence that fits it, and check whether the comparison is fair.[1]

Fast lesson

Use these checks before you answer the practice questions.

Read headings first

Identify what each column means before describing a pattern.

Hold one condition steady

The table assumes the same one-metre stick across all rows.

Use numbers as evidence

Cite at least two values when describing the pattern.

Common mistakes

Treating the table as a universal timetable.

Why this fails: Real shadow lengths depend on date, location, object height and surface geometry.

Describing only the numbers.

Why this fails: The table shows a pattern; the prose explains the mechanism.

Saying the shadow keeps shrinking all afternoon.

Why this fails: The illustrative value rises from 1.0 m at 13:00 to 1.6 m at 15:00.

Word Lab

Use the meaning, hear the word, then try it in your own sentence.

shadow

noun

A darker area where an object blocks light.

The tree cast a long shadow.

apparent

adjective

Seeming to be a certain way from an observer’s point of view.

The Sun’s apparent path changes across the sky.

angle

noun

The amount of turn between two directions or lines.

A low sunlight angle can make a long shadow.

vertical

adjective

Straight up and down.

The class used a vertical stick.

pattern

noun

An organized way values change.

The table shows a down-then-up pattern.

controlled

adjective

Kept the same so a comparison is fairer.

The stick height was controlled across rows.

Check your understanding

Choose an answer, explain your choice, and then check. Hints and retries are welcome.

Illustrative classroom data for a one-metre stick—not measurements from a specific place or date.
TimeShadow length
9:002.4 m
11:001.3 m
13:001.0 m
15:001.6 m
Main idea1. Why can the same stick have different shadow lengths during one day?
Show answer and explanation

Answer: Earth’s rotation changes the Sun’s apparent position and light angle.. Earth’s rotation changes the Sun’s apparent position and therefore the light angle.

Table evidence2. Which listed time has the shortest illustrative shadow?
Show answer and explanation

Answer: 13:00. The smallest listed value is 1.0 m at 13:00.

Synthesis3. Which statement best combines the text and table?
Show answer and explanation

Answer: The table shows a shorter shadow near the middle rows, matching the higher-Sun/shorter-shadow explanation.. The data shrink toward 13:00 then rise, consistent with the text’s geometry.

Try the questions here. Public practice does not save a learning record.

Foundation

Foundation practice

Read exact values and variables.

Table lookup

1. What is the illustrative shadow length at 9:00?

  1. 2.4 m
  2. 1.3 m
  3. 1.0 m
  4. 1.6 m
Table lookup

2. What is the illustrative shadow length at 15:00?

  1. 2.4 m
  2. 1.3 m
  3. 1.0 m
  4. 1.6 m
Variable

3. What stays the same in the table?

Pattern

4. What short phrase describes all four rows?

Core

Core practice

Connect numerical evidence to the explanation.

Compare

5. How much shorter is the 13:00 shadow than the 9:00 shadow?

Compare

6. From 13:00 to 15:00, does the shadow shorten or lengthen?

Synthesis

7. How do the prose and table work together?

Claim check

8. Does the table prove that 13:00 is always the shortest-shadow time everywhere?

Think

Think practice

Use calculations, limitations and causal reasoning to combine the table with the text.

Sequence

9. Put the illustrative shadow lengths in order from shortest to longest.

Difference

10. How much longer is the 9:00 shadow than the 11:00 shadow?

Evidence

11. Which two rows show the shadow beginning to lengthen again?

Mechanism

12. Why does a lower Sun angle make a longer shadow?

Source distinction

13. Are the four table values NASA measurements?

Fair comparison

14. Name two conditions that should stay the same while comparing times.

Overclaim

15. Why is 'shadows are always shortest at exactly 13:00' too strong?

Synthesis

16. Complete the reasoning: Earth rotates → the Sun’s apparent position changes → ______.

Evidence writing

17. Which sentence is strongest evidence language?

  1. The shadow changes a lot.
  2. The shadow is shorter sometimes.
  3. In the illustrative table, the shadow falls from 2.4 m at 9:00 to 1.0 m at 13:00 before rising to 1.6 m at 15:00.
  4. The Sun makes shadows.

Practice answer key

  1. 1. 2.4 m
    Read the first row.
  2. 2. 1.6 m
    Read the last row.
  3. 3. The one-metre stick and assumed setup.
    Keeping the object fixed makes the comparison stronger.
  4. 4. The shadow gets shorter, reaches the shortest listed value, then gets longer.
    The values are 2.4, 1.3, 1.0 and 1.6 m.
  5. 5. 1.4 m shorter.
    2.4 − 1.0 = 1.4.
  6. 6. It lengthens by 0.6 m.
    The value rises from 1.0 m to 1.6 m.
  7. 7. The prose explains changing sunlight angle; the table gives numerical examples of the shadow pattern.
    Mechanism plus data makes a stronger explanation.
  8. 8. No.
    The data are illustrative, and real solar timing depends on place and date.
  9. 9. 1.0 m, 1.3 m, 1.6 m, 2.4 m.
    Ordering the values helps reveal the shape of the pattern.
  10. 10. 1.1 m.
    2.4 − 1.3 = 1.1.
  11. 11. 13:00 at 1.0 m and 15:00 at 1.6 m.
    The later value is larger, showing the turn upward.
  12. 12. The light reaches the ground more shallowly, so the blocked region stretches farther.
    The geometry in the text links shallow light angle with longer ground distance.
  13. 13. No. They are original illustrative Study Commons data.
    The lesson explicitly labels the dataset as illustrative.
  14. 14. For example, object height and location.
    Holding important conditions constant makes the rows more comparable.
  15. 15. The exact timing depends on date and location, and the table is illustrative.
    The data support the lesson pattern, not a universal clock rule.
  16. 16. the sunlight angle changes, so the shadow length changes.
    This connects cause, mechanism and observed result.
  17. 17. In the illustrative table, the shadow falls from 2.4 m at 9:00 to 1.0 m at 13:00 before rising to 1.6 m at 15:00.
    It cites several exact values and describes the full pattern.

Related skills

Why Earth Has SeasonsHow Rainbows FormWhy Metal Feels Colder Than Wood

Put it in your own words

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Check your own explanation

This is self-review, not automatic marking.

Compare with a model response

Earth’s rotation makes the Sun appear to change position across the sky, so the sunlight angle changes. In the illustrative table, the shadow drops from 2.4 m at 9:00 to 1.0 m at 13:00, then rises to 1.6 m at 15:00. This fits the explanation that a higher Sun makes a shorter shadow. Exact times and lengths vary by place and date.

Sources and revision notes

Source check: 2026-10-01. Grade guidance is an editorial suggestion, not a standardised reading score.

  1. NASA Science — Our World: Sun’s Position
  2. NASA Science — Tropical Solstice Shadows
What changed in this edition?

Initial release. Claims about the Sun’s apparent position, Earth’s rotation and low-Sun-angle shadows were checked against NASA Science on 2026-10-01. The four-row shadow table is an original illustrative dataset, not a real measurement series.

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