Output The disturbance reaches a given underwater distance sooner Input The same sound-frequency disturbance moving through air and liquid water Why does sound travel faster in water than in air? AnswersGeneral
Output The warmer parcel moves upward until forces and temperature differences change Input A parcel of air warmed relative to surrounding air Why does warmer air tend to rise? AnswersGeneral
Output An approximately spherical bubble Input A flexible soap film enclosing air away from nearby surfaces Why are free soap bubbles round? AnswersGeneral
Output Less glare and clearer detail beneath or beyond the reflection Input A camera viewing reflective water through a rotated polarising filter A polarising filter can reduce reflected glare CausesLearning
Output Composite Input Background Lower opacity blends a foreground with its background TransformsLearning
Output Combined inks Input Cyan Cyan, magenta and yellow inks combine toward a dark neutral ProducesLearning
Output Ice remains partly above the liquid surface Input A piece of freshwater ice placed in liquid freshwater Ice floats because its solid structure is less dense CausesLearning
Output Paper pieces lift toward and may cling to the comb Input A charged plastic comb held close to tiny neutral paper pieces A static charge attracts small paper pieces CausesLearning
Output A drier surface at a lower temperature than before evaporation Input Liquid water spread across a warm surface with moving dry air Evaporation cools a wet surface CausesLearning
Output A star that appears to shimmer Input Light from a distant star passing through Earths atmosphere Why do stars twinkle? AnswersGeneral
Output A delayed repetition of the original sound Input A short sound made near a large hard surface Why does an echo return? AnswersGeneral
Output Opposite seasonal cycles in the northern and southern hemispheres Input Earth orbiting the Sun with its axis tilted about 23.5 degrees Why does Earth have seasons? AnswersGeneral
Output Predictable rises and falls in coastal water level Input Earth, its oceans, the Moon and the Sun Why do oceans have tides? AnswersGeneral
Output A repeating sequence from new Moon through full Moon and back Input The Moon orbiting Earth while the Sun lights half of it Why does the Moon have phases? AnswersGeneral
Output A sustained path of moving indoor air Input Two open windows on different sides of a room Openings on opposite sides create cross-ventilation CausesLearning