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One question set, multiple game modes. Tap any game to see it in action. Not sure which to pick?
Answer to place stones and capture territory.
Outrun the snow together.
Earn blasts, then hunt the other team.
Answer to earn energy, then climb.
The class blasts through walls together.
Bid on mystery lots. Most money wins.
Sell tours. Nice, standard, or a total scam.
Answer, restock, and serve the rush.
More correct answers pulls the rope your way.
Answer, then shoot down the alien wave.
Answer, then tap to leap the frozen ridge.
A pebble has density 3 g/cm3. Water rises from 35 to 44 cm3. What is its mass?
A uniform block is cut into two equal pieces. How does each piece's density change?
A solid has density 1050 kg/m3. Water: 1000; salt solution: 1100. Where does it float?
A block has a mass of 200 g and a volume of 80 cm3. What is its density?
A liquid has a mass of 120 g and a density of 1.5 g/cm3. What is its volume?
Oil has a density of 0.8 g/cm3. What is this in kg/m3?
Three blocks have equal volumes and masses of 40 g, 55 g and 70 g. Which is most dense?
A wooden block is held fully underwater and released. What usually happens first?
A toy boat floats at rest. How do the upthrust and its weight compare?
Why can a hollow steel ship float even though solid steel is denser than water?
True or False: An object that sinks in water must also sink in every denser liquid.
True or False: If the mass and volume of a sample both double, its density stays the same.
A block has a mass of 45 g and a volume of 15 cm3. Enter its density in g/cm3 (number only).
Complete the equation: density = mass / ____.
A cork floats in water. Its average density is ____ than water's. Enter higher or lower.
Which measurements are needed to find the density of an irregular pebble? Select all correct answers.
A vacuum in a flask reduces heat transfer by blocking which two processes?
Why does water left in a puddle cool as it evaporates?
A motor receives 360 J and gives 225 J of useful energy. How much energy is wasted?
To compare cup insulation fairly, what should be the same at the start?
Metal and wood are at the same room temperature. Why does the metal feel colder?
Blocks at 20 oC and 60 oC touch. In which direction does thermal energy flow overall?
How do particles mainly pass thermal energy along a solid glass rod?
Which sequence helps warm air rise in a convection current?
Which process transfers energy from the Sun across space to Earth?
Which surface is usually the best absorber of infrared radiation?
Three cups start at 80 oC. After 5 min, A is 68 oC, B is 75 oC and C is 71 oC. Which has the best insulation?
A machine receives 500 J and transfers 350 J usefully. An improvement reduces the waste by 40 J. For the same input, what is the new useful output?
True or False: Thermal energy can transfer through a vacuum by radiation.
True or False: Evaporation only happens at the boiling point.
True or False: An inefficient machine destroys the energy that is not useful.
What is the SI unit of energy? Write the unit name, not its symbol.
Water cools from 72 oC to 49 oC. Enter the temperature fall in oC (number only).
Which changes usually increase evaporation from a shallow dish of water? Select all correct answers.
A loudspeaker cone moves back and forth. How does it make sound?
A sound makes 80 complete vibrations in 2 s. What is its frequency?
Which pair of units is correct: frequency, then sound level?
Which change reduces the risk from loud headphones?
Which description matches a rarefaction in a sound wave in air?
Air is slowly removed from around a ringing electric bell. What happens to the sound heard outside?
Which change makes a sound higher pitched without changing its amplitude?
Sound B has twice the frequency of A but the same amplitude. Which comparison is correct?
Two identical waves each have amplitude 3 mm. Their peaks meet exactly. What is the combined amplitude?
Two waves meet. Their displacements at one point are +3 mm and -2 mm. What is the resulting displacement?
A source makes 44000 vibrations in 2 s. Which statement describes its frequency and usual human hearing?
Two students hear the same loud sound. One listens for 10 s and the other for an hour. Who has the greater hearing risk?
True or False: Sound can transfer energy without medium.
True or False: A louder sound always has a higher pitch.
What is the unit of frequency? Write the unit name, not its symbol.
A wave makes 18 complete vibrations in 3 s. Enter its frequency in Hz (number only).
Pitch depends on the ____ of a sound. Enter frequency or amplitude.
Which statements about sound are correct? Select all correct answers.
Which change usually makes both lamps in a series circuit brighter?
At fixed voltage, increasing a variable resistor's resistance makes the current...
A lamp transfers 180 J in 45 s. What is its power?
One lamp's filament breaks. The other stays lit. Which arrangement explains this?
Which connections correctly measure the current through and voltage across a lamp?
A resistor has 6 V across it and carries a current of 0.3 A. What is its resistance?
Three identical lamps are in series across a 9 V supply. What voltage is across each lamp?
Two lamps are connected in parallel across a 12 V supply. What voltage is across each lamp?
A total current of 0.90 A splits into three branches. Two carry 0.25 A and 0.35 A. What does the third carry?
A student tests how wire length affects resistance. Which other properties should stay the same?
Two wires have the same material, length and temperature. Which has the greater resistance?
True or False: Current is used up as it passes through each lamp in a series circuit.
True or False: Two parallel branches always carry equal currents, even if their resistances differ.
True or False: A longer wire has greater resistance if its material, thickness and temperature stay the same.
A 0.5 W lamp operates for 20 s. Enter the energy transferred in J (number only).
A 4 ? resistor has 8 V across it. Enter its current in A (number only).
Which statements about a simple series circuit are correct? Select all correct answers.
To test how drop height affects crater size, which variable should stay the same?
After a large impact, dust blocks sunlight for months. Which effect is most likely?
Which finding supports Earth and Moon forming from similar material?
What is nebula?
According to the Big Bang theory, how did the early Universe compare with the Universe today?
A student says redshift means distant galaxies are moving towards us. Which correction is needed?
Which sequence best matches the collision theory of Moon formation?
The Moon has a smaller iron core relative to its size and a lower average density than Earth. What does this support?
A student changes drop height in a ball-and-flour impact model. Which measurement shows the crater size?
How can a student improve the reliability of crater-diameter results at each drop height?
Which stage comes next after a star like the Sun leaves its stable main-sequence stage?
Which sequence correctly shows the later stages predicted for a Sun-like star?
True or False: A white dwarf is predicted to cool and fade into a black dwarf over an extremely long time.
Which force pulls gas and dust together to form stars? Enter one word.
Crater diameters under the same conditions are 10, 11, 25 and 10 cm. Which value should be checked as an anomaly? Enter the number only.
Which findings support the collision explanation for Moon formation? Select all correct answers.
Crack the passcode before the zombies get in.
Answer, then swat bugs for bonus points.
Race through questions at your own speed.
Same question on every screen. Fastest wins.
Pick a tile, answer, hit bonuses and steals.
21 questions
