Demo. An invented family, made-up minutes, nobody's real child. The quizzes work: pass a round and watch the clock change.

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⚛️ Physics, NCEA

Years 11 to 13 · Read up first

10 questions. Get 8 right to earn 10 minutes. All 10 right = +5 bonus. They start easy and get harder as you go, so treat the first few as a warm-up. Every one you miss comes back with the answer and why.

1. Refraction is the

splitting of light into colours onlyabsorption of light by a black surfacebending of light as it passes from one medium into anotherbouncing of light off a surface

2. Which quantity describes how fast an object's velocity is changing?

MassDisplacementSpeedAcceleration

3. Work done is calculated as

force divided by distanceforce times timeforce times distance moved in the direction of the forcemass times velocity

4. An object moving in a circle at constant speed is still accelerating because

acceleration only depends on speed, not directionits speed is always increasingits direction (velocity) is constantly changing, even though its speed is notthere is no force acting on it

5. The wave equation relates wave speed, frequency and wavelength as

speed = frequency times wavelengthspeed = frequency divided by wavelengthspeed = frequency plus wavelengthspeed = frequency minus wavelength

6. Sound cannot travel through

air only, but works fine in liquids and solidssolidswatera vacuum, since sound needs particles of a medium to travel through

7. Radioactive decay is a

process that never actually happens in naturerandom process for any individual nucleus, but predictable in large numbersperfectly predictable process for each individual atomprocess that can be sped up by heating the sample

8. For an object moving in a circle, the centripetal acceleration points

away from the centre of the circleopposite to the direction of traveltowards the centre of the circlein the direction of travel

9. Two identical cars travel at the same speed around two different bends: Bend A has a small radius, Bend B has a large radius. Which car needs a greater centripetal force to stay on its path?

Neither needs any centripetal forceThe car on Bend A (small radius), since centripetal force increases as radius decreasesThe car on Bend B (large radius), since force increases with radiusBoth need exactly the same force

10. A magnet is pushed into a coil of wire connected to a sensitive meter. According to the principle of electromagnetic induction, a current is induced in the coil because

the magnetic field through the coil is changing, which induces an electromotive force (voltage) that drives a currentthe coil's wire becomes magnetised permanentlycurrent only flows if the magnet touches the wire directlythe magnet loses its magnetism as it enters

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