Northstar Learning › Brain Lab
Scientific reasoning challenges
Think-it-through questions on scientific reasoning, from teen to adult level, each with a clear explanation.
16 questions · free · no account needed · works offline once loaded
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Where does energy go when a moving object slows due to friction?
Options: Mostly to thermal energy in the surroundings · It vanishes · It becomes new matter
Answer: Mostly to thermal energy in the surroundings
Friction transfers kinetic energy, often heating surfaces and surroundings.
To compare two paper-plane designs, what should stay the same?
Options: Both design and throwing force · Throwing method and launch point · The person measuring each time
Answer: Throwing method and launch point
Control other conditions so design is the main changed factor.
A book rests on a table. Which forces balance vertically?
Options: Two downward forces · Weight downward and support force upward · No forces act
Answer: Weight downward and support force upward
The table's support force balances the book's weight.
Why is a controlled experiment often stronger than observation for causality?
Options: It can isolate an intervention under planned conditions · It removes measurement error · It always represents every population
Answer: It can isolate an intervention under planned conditions
Control improves causal inference, though generalisation still needs care.
A result is measured once with a noisy instrument. What improves reliability?
Options: Round every number to a whole value · Repeat measurements and compare spread · Change several variables together
Answer: Repeat measurements and compare spread
Repeats help estimate variation and identify anomalous readings.
A car travels 150 km in 3 hours. What is its mean speed?
Options: 450 km/h · 50 km/h · 45 km/h
Answer: 50 km/h
Mean speed is distance divided by time: 150 ÷ 3 = 50.
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