Saturn's Rings — Particle Collisions & Energy Transfer
GED Science Practice — Reading tables, data analysis & scientific reasoning
Read the passage
Saturn's rings contain enormous numbers of particles. These particles sometimes experience collisions with each other. Scientists need to know how those collisions transfer energy in order to model the overall structure and composition of the rings. Images of particles in Saturn's rings reveal that only 50–60% of the particles' energy remains after a collision. To identify which types of particles could explain the observations, a scientist tests substances in a laboratory and measures the energy remaining after collisions between particles of those substances. The table shows the scientist's results.
Energy in Particles After a Collision
Material
Energy Remaining
bedrock
95%
carbon rock
83%
ice
50%
loose rocks
24%
loose snow
20%
GED question: Based on these results and assuming that whenever two materials are present their remaining energy is averaged, what would the scientist best conclude to be the composition of Saturn's rings?
You may use the calculator.
○ equal amounts of loose rocks and loose snow
○ equal amounts of ice and bedrock
○ a small amount of bedrock and a large amount of carbon rock
● large amounts of ice and smaller amounts of carbon rock
Work through each tab to understand why the highlighted answer is correct and why the others are wrong.
Saturn's rings — drag to rotate & explore
⇦ Drag to rotate | Pinch or scroll to zoom
Saturn's rings are made of billions of particles that constantly collide with each other
What is this question about?
Saturn's rings contain enormous numbers of particles. When particles collide, some of their kinetic energy is lost (transferred as heat, sound, or deformation). Scientists observed that in Saturn's rings, only 50–60% of particle energy remains after a collision.
A scientist then tested 5 different materials in a lab, measuring energy remaining after collisions. The question asks: based on the data, what is the best conclusion about the composition (what it's made of) of Saturn's rings?
Key rule: When two materials are present in equal amounts, their remaining energy values are averaged.
Target range
Scientists measured 50–60% energy remaining in Saturn's ring collisions. The correct answer must match this range.
Averaging rule
If two materials are present equally, add their energy values together and divide by 2. This gives the combined energy remaining.
Energy remaining
Higher % = material keeps more energy after collisions (like hard, bouncy surfaces). Lower % = more energy lost (soft, absorbent materials).
Composition
What something is made of. Saturn's rings could be rock, ice, snow — or a mixture. The data tells us which fits the observations.
Energy in particles after a collision
Lab results — energy remaining after collisions between particles of each material.
Material
Energy Remaining After Collision
Matches 50–60% target?
Bedrock
95%
✗ Too high (way above 60%)
Carbon rock
83%
✗ Too high (above 60%)
Ice
50%
✓ Matches perfectly!
Loose rocks
24%
✗ Too low (below 50%)
Loose snow
20%
✗ Too low (below 50%)
Key observation: Ice alone (50%) already falls within the 50–60% target. Bedrock alone (95%) falls far outside the range. We need to find what combination — if any — also hits 50–60%.
Visualizing energy remaining by material
The green zone (50–60%) is the target range based on Saturn's ring observations. Only ice and certain combinations hit this zone.
Understanding what "energy remaining" means
High % (bedrock 95%)
Very hard, rigid material — particles bounce off each other efficiently, retaining almost all their energy. Like billiard balls colliding.
Low % (loose snow 20%)
Very soft, compressible material — particles absorb much of the collision energy, converting it to heat and deformation. Like snowballs hitting each other.
Medium % (ice 50%)
Ice is between hard rock and soft snow — firm enough to retain half its energy but still absorbs some in each collision.
Why it matters
Saturn's ring particles retain 50–60% energy per collision. This is the "fingerprint" that lets scientists identify what the rings are made of.
Calculating combined energy for each answer choice
When two materials are present in equal amounts, average their energy values: (A + B) ÷ 2. The result must fall in the 50–60% target range to match Saturn's observations.
Answer choice
Energy A
Energy B
Average (A+B)÷2
In 50–60%?
Equal amounts of loose rocks + loose snow
24%
20%
22%
✗ Too low
Equal amounts of ice + bedrock
50%
95%
72.5%
✗ Too high
Small bedrock + large carbon rock (Not equal amounts — cannot simply average)
95%
83%
~89%+
✗ Way too high
Large ice + smaller carbon rock (Mostly ice, some carbon rock)
50%
83%
~55–60%
✓ In range!
Wait — why is "equal amounts of ice and bedrock" WRONG even though it's the selected answer? Let's look again: (50 + 95) ÷ 2 = 72.5%. That is NOT in the 50–60% range. The correct answer is large amounts of ice and smaller amounts of carbon rock — because ice (50%) weighted more heavily with some carbon rock (83%) can land in the 55–60% zone.
Step-by-step working for the correct answer
Large ice + smaller carbon rock calculation
Ice energy remaining:50%
Carbon rock energy remaining:83%
Equal mix average:(50 + 83) ÷ 2 = 66.5%
Equal mix is slightly above the range. But "large amounts of ice + smaller amounts of carbon rock" means MORE ice (50%) and LESS carbon rock (83%) — shifting the weighted average DOWN toward 55–60%.
Target range: 50–60%
With mostly ice (50%) and some carbon rock (83%):
Weighted average = closer to 50% (ice-dominant) → lands ~55–60% ✓
Try it yourself — mix two materials
Select two materials and a mixing ratio to see the combined energy remaining. Find what hits the 50–60% target!
Energy combination calculator
Select materials above to see the result.
Challenge: Can you find at least 2 different combinations that land in the 50–60% range? Try mixing ice with small amounts of carbon rock, or equal amounts of loose rocks and carbon rock.
All single materials — do any hit 50–60%?
Material
Energy Remaining
In 50–60% range?
Bedrock
95%
✗ No — too high
Carbon rock
83%
✗ No — too high
Ice
50%
✓ Yes! Exactly at lower bound
Loose rocks
24%
✗ No — too low
Loose snow
20%
✗ No — too low
Ice alone (50%) just hits the bottom of the target range. Combining large ice + smaller carbon rock raises it into the 55–60% zone — a stronger fit for the full 50–60% window.
Breaking down all four answer choices
"Based on these results, what would the scientist best conclude to be the composition of Saturn's rings?"
WRONG
"Equal amounts of loose rocks and loose snow"
Calculation: (24% + 20%) ÷ 2 = 22%
This is far below the 50–60% target. Both materials lose too much energy in collisions. ✗
WRONG
"Equal amounts of ice and bedrock"
Calculation: (50% + 95%) ÷ 2 = 72.5%
This is well above the 50–60% target. Bedrock retains too much energy, pulling the average too high. ✗
WRONG
"A small amount of bedrock and a large amount of carbon rock"
Even mostly carbon rock (83%) with a small bit of bedrock (95%) gives an average well above 83% — far above the target. Both materials are too high individually. ✗
CORRECT
"Large amounts of ice and smaller amounts of carbon rock"
Ice = 50%, Carbon rock = 83%. Equal mix = 66.5% (slightly above).
But with more ice than carbon rock, the weighted average shifts closer to ice's 50% — landing in the 55–60% zone. This is the only combination that fits within 50–60%. ✓
GED strategy — data table reasoning questions
Step 1: Identify the target — what value or range must the answer match? (Here: 50–60%)
Step 2: Check if any single material matches the target first
Step 3: For combinations, apply the averaging rule: (A + B) ÷ 2
Step 4: Eliminate choices whose calculation falls outside the target range
Step 5: Consider unequal mixing — "large A + small B" weights A more heavily in the average
Rule of thumb: When the question says "whenever two materials are present their remaining energy is averaged" — always do the math. Do not guess based on intuition. Calculate each option and compare to the target range.
Correct answer: Large amounts of ice and smaller amounts of carbon rock. Reasoning: Ice (50%) + carbon rock (83%), weighted toward more ice, gives ~55–60% — the only combination that falls within Saturn's observed 50–60% energy-remaining range.
