OpenStem

@openstem · Joined Jul 2026

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Quiz6 questions

Which law says that an object at rest stays at rest unless a force acts on it?

ANewton's First LawBNewton's Second LawCNewton's Third LawDThe law of gravity

Physics

Physics · L2 · Newton's Three Laws

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Quiz6 questions

In a series circuit, how many paths does electricity have to flow through?

AOnly oneBExactly twoCAs many as there are bulbsDIt depends on the battery

Physics

Physics · L2 · Series & Parallel Circuits

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Quiz6 questions

What is refraction?

ALight bouncing straight back off a mirrorBLight bending as it passes from one material into anotherCLight splitting into different coloursDLight disappearing when it hits glass

Physics

Physics · L2 · Refraction & Lenses

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Quiz6 questions

A metal spoon left standing in a pot of hot soup slowly becomes warm all along its handle. Which type of heat transfer is this?

AConductionBConvectionCRadiationDEvaporation

Physics

Physics · L2 · Heat Transfer

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Quiz6 questions

A block has a mass of 30 g and a volume of 10 cm³. What is its density?

A0.3 g/cm³B3 g/cm³C300 g/cm³D20 g/cm³

Physics

Physics · L2 · Density & Buoyancy

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Quiz6 questions

Which idea best describes pressure?

AHow heavy an object isBForce spread over an areaCHow fast an object movesDThe total energy an object has

Physics

Physics · L2 · Pressure: Atmospheric & Fluid

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Quiz6 questions

What creates the magnetic field in an electromagnet?

AThe iron nail alone, even without currentBElectric current flowing through the coiled wireCThe battery's plastic casingDFriction between the wire and the nail

Physics

Physics · L2 · Magnetism & Electromagnets

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Quiz6 questions

A force of 8 N moves a box 3 m in the direction of the force. How much work is done?

A24 JB11 JC5 JD2.67 J

Physics

Physics · L2 · Work & Power

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Quiz6 questions

What two things does an object's momentum depend on?

AIts color and shapeBIts mass and its speedCIts temperature and its materialDOnly its speed

Physics

Physics · L2 · Momentum & Collisions

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Quiz5 questions

What actually happens when you rub a balloon on your hair?

AElectrons move from your hair onto the balloonBThe balloon becomes magneticCNew electrons are created inside the balloonDNothing changes — rubbing has no effect

Physics

Physics · L2 · Static Electricity

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Quiz5 questions

What does voltage do in a circuit?

AIt pushes current through the circuitBIt slows current downCIt has nothing to do with currentDIt stores current permanently

Physics

Physics · L2 · Introducing Ohm's Law

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Quiz5 questions

What makes a bar magnet a 'permanent' magnet?

AIt needs a battery to stay magneticBIt is magnetic all on its own, without any electricityCIt only works when a switch is turned onDIt loses its magnetism after a few minutes

Physics

Physics · L2 · Permanent Magnets & Field Lines

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Quiz5 questions

Which direction does friction act, relative to the motion (or attempted motion) of an object?

AIn the same direction as the motionBOpposite to the direction of the motion or attempted motionCStraight up, away from the surfaceDFriction has no particular direction

Physics

Physics · L2 · Friction

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Quiz5 questions

What does a wave carry from one place to another as it travels?

AThe matter of the medium itself, all traveling togetherBEnergy, without carrying the medium's matter along with itCNothing — a wave is just an appearance with no real transportDOnly sound, never light or water

Physics

Physics · L2 · Wave Basics

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Quiz5 questions

What is a trajectory?

AThe curved path a thrown or launched object follows through the airBThe exact spot where a ball landsCThe force used to throw an objectDThe speed of an object at the moment of release

Physics

Physics · L2 · Projectile Motion Basics

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Quiz5 questions

What determines the pitch of a sound?

AHow big the vibration isBHow fast the source vibrates (its frequency)CHow far away the listener isDWhat color the vibrating object is

Physics

Physics · L2 · Sound: Pitch, Loudness & Echoes

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Quiz5 questions

What is the center of mass of an object?

AThe point where all of its weight seems to act from — its overall balance pointBThe exact geometric center of every object, no matter how its weight is spread outCThe point where an object is glued or bolted to the groundDThe single heaviest atom inside the object

Physics

Physics · L2 · Center of Mass & Stability

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Quiz5 questions

Which way does a concave mirror curve?

AInward, like the inside of a spoonBOutward, like the back of a spoonCIt stays perfectly flatDIt curves in a random, uneven way

Physics

Physics · L2 · Curved Mirrors

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Quiz5 questions

What is periodic motion?

AMotion that repeats itself over and over in a regular patternBMotion that only happens once and then stopsCMotion that always speeds up over timeDMotion that only occurs in outer space

Physics

Physics · L2 · Pendulums & Periodic Motion

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Quiz6 questions

What does a mechanical advantage of 3 mean?

AThe machine makes the load 3 times heavierBThe machine multiplies your input force by 3CThe machine takes 3 times as long to useDThe machine has 3 moving parts

Physics

Physics · L2 · Mechanical Advantage: Levers & Pulleys

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Quiz6 questions

A device draws 4 A of current at 100 V. What is its power?

A25 WB104 WC400 WD40 W

Physics

Physics · L2 · Electrical Power & Energy

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Quiz6 questions

What generally happens to a material's size when it's heated?

AIt shrinksBIt expandsCIt stays exactly the same sizeDIt always melts

Physics

Physics · L2 · Thermal Expansion

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Quiz6 questions

What does a magnetic field line represent at any point along it?

AThe temperature at that pointBThe direction a compass needle would point thereCThe color of the magnetDThe exact weight of the magnet

Physics

Physics · L2 · Magnetic Field Lines & Earth's Magnetism

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Quiz6 questions

What is an echo?

AA sound that gets louder on its ownBA sound wave reflecting off a surface and returning to your earsCA sound that changes pitch as it travelsDSilence after a loud noise

Physics

Physics · L2 · Echoes, Sound Reflection & Sonar

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Quiz6 questions

What does Hooke's Law, F = kx, describe?

AThe relationship between a spring's mass and its lengthBThe force needed to stretch or compress a spring by a given amountCHow fast a spring vibrates over timeDThe temperature at which a spring melts

Physics

Physics · L2 · Springs & Hooke's Law

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Quiz6 questions

A 4 kg object accelerates at 2 m/s². What net force acts on it?

A2 NB6 NC8 ND4 N

Physics

Physics · L3 · Newton's Second Law

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Quiz6 questions

An object travels in a circle at constant speed. Which direction does its acceleration point?

AOutward, away from the centerBToward the center of the circleCIn the direction of travelDIt has no acceleration since its speed is constant

Physics

Physics · L3 · Circular Motion & Centripetal Force

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Quiz6 questions

Which formula correctly gives the gravitational force between two masses?

AF = G·m₁·m₂/r²BF = G·m₁·m₂·r²CF = G·(m₁ + m₂)/rDF = G/(m₁·m₂·r)

Physics

Physics · L3 · Universal Gravitation

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Quiz6 questions

What is the formula for momentum?

Ap = m + vBp = mvCp = m/vDp = ½mv²

Physics

Physics · L3 · Conservation of Momentum

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Quiz6 questions

Which equation correctly states the work-energy theorem?

AW_net = ΔKE = ½mv_f² − ½mv_i²BW_net = F × d, with no connection to speedCF = maDKE = mv, without a square or a factor of ½

Physics

Physics · L3 · Work-Energy Theorem

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