Extinction Theories
If scientists found tsunami debris but no shocked quartz at a site, which hypothesis would be more supported — asteroid or volcanism — and why?
Asteroid hypothesis — tsunamis are consistent with an asteroid impact that could generate massive waves.
A scientist finds that students who bring energy drinks to school also get lower grades. Suggest two different explanations — one correlational and one causal.
Correlation: Tired students both drink energy drinks and struggle to focus. Causation: The caffeine/sugar crashes might affect performance.
A boulder is sitting at the top of a hill. Describe two different ways its potential energy could turn into kinetic energy.
Rolling downhill or falling off an edge — both convert gravitational potential to kinetic.
If you slid a book across ice vs across carpet, which of Newton's laws explains the difference in how far it travels?
Newton’s First Law — friction acts as an unbalanced force stopping motion faster on carpet.
A roller coaster climbs slowly to the top of a hill and then drops quickly. Describe how kinetic and potential energy change during both parts of the ride.
Going up: Potential energy increases, kinetic decreases. Going down: Potential energy decreases, kinetic increases.
Different hypotheses explain dinosaur extinction. Which one best explains a global increase in atmospheric radiation, and why?
Supernova hypothesis — because a nearby supernova could release radiation affecting Earth's atmosphere.
Why is it dangerous to assume causation when only correlation is shown in data?
It can lead to incorrect conclusions or bad decisions (e.g., blaming the wrong cause).
If two objects have the same kinetic energy but different masses, what can you infer about their speeds?
The lighter object must be moving faster.
Two objects interact: a car bumps a shopping cart. According to Newton’s Third Law, they exert equal forces — so why does the cart move more?
Newton’s Second Law — the cart has less mass, so it accelerates more under the same force.
A student claims that “the heavier object will always hit the ground faster than a lighter one.” Based on what you’ve learned, explain whether this is true or false and why.
False — if only gravity acts (no air resistance), they accelerate at the same rate; mass does not affect gravitational acceleration.
Why was finding iridium all over the world, not just near the Yucatán Peninsula, important evidence for the asteroid hypothesis?
It showed the impact spread debris globally, meaning the event was powerful enough to affect Earth’s entire environment.
Give an example of a correlation that could hide a third factor (a confounding variable).
Confounding: not directly measured, but influences both variables
Students who wear glasses read more books — the hidden factor is interest in reading or vision needs, not the glasses themselves.
OR
Kids who play video games get worse grades.Less study time or staying up late
Why is energy considered “never lost” even in a collision where objects stop moving?
It transforms into other forms like sound, heat, or deformation.
A magician pulls a tablecloth from under dishes without moving them. Which law is being demonstrated and how?
Newton’s First Law — the dishes resist change in motion (inertia), so they stay in place.
If scientists could recreate a small asteroid impact in a lab, which three types of evidence from the dinosaur extinction could they try to reproduce to support the asteroid hypothesis?
Shocked quartz, glass spheres (tektites), and tsunami-like sediment patterns.
In science, why is it important to use multiple lines of evidence (like glass spheres and shocked quartz) instead of just one clue?
One clue could be coincidence, but multiple independent clues strengthen a conclusion.
If two variables move in opposite directions, how could that lead scientists to wrongly assume negativity even if the relationship is positive?
They might mistake coincidence or an indirect effect for a meaningful negative trend.
A student argues that only moving objects can do work. Use potential energy to prove them wrong.
A stretched bow or lifted weight can release stored energy to do work even when still.
Why: Potential energy = stored energy that can do work in the future.
Objects don’t need to be moving right now to do work; they just need energy that can be released to move something.
If two students push each other on skateboards, why do both move, even if one is stronger?
Action and reaction forces are equal; both receive force, but motion depends on their mass.
A bowling ball and a tennis ball are thrown with the same force. Using Newton’s Second Law, explain which will accelerate more and why.
The tennis ball — it has less mass, so the same force causes greater acceleration.
If future technology found no crater at Yucatán, but iridium levels remain high, which hypothesis might become more accepted — and why?
Volcanism hypothesis — because without a crater, iridium might be traced to volcanic eruptions instead of impact.
Suggest a situation where correlation eventually leads scientists to discover causation.
Kids who ate more fruits and vegetables had fewer colds — later research confirmed that vitamins and nutrients boost immunity.
OR
Students who studied in quiet rooms did better on exams — later research confirmed that fewer distractions improve learning.
If a force is applied to an object but it doesn’t move, is work being done in scientific terms? Explain.
No — work requires movement in the direction of the force.
If a rocket launches upward, explain how each of Newton’s 3 laws is demonstrated in different parts of the launch.
1st: Rocket stays still until engine force.
2nd: More force → more acceleration.
3rd: Exhaust gases push down, rocket moves up.
During a collision, some energy is transformed into sound and heat. How does this demonstrate the law of conservation of energy?
It shows that energy is not lost, only transferred or transformed into different forms.