Check which variables changed, which were shared and what your explanation predicts.
Compare the water paths
Two plots receive the same rain. On one plot, a roof-like surface directs water to an outlet. On another, permeable soil allows some water to enter below the surface. A lower outlet volume on soil is consistent with infiltration, but evaporation and temporary pooling could also reduce collected volume.
A below-ground moisture sensor can help distinguish pathways. If the same soil is already saturated during a second storm, its lower capacity for storing new water may increase runoff. A good comparison describes surface conditions and rainfall together.
Compare the hemispheres
At comparable latitudes, a longer day in one hemisphere and a shorter day in the other challenge an explanation based only on the whole Earth moving closer to the Sun. The tilt model predicts a difference in the portion of each rotation spent in sunlight.
Use a lamp and a tilted globe to test the prediction. Keep the axis orientation fixed relative to the room as the globe moves. What changes across the orbit is which axis end leans toward the lamp, along with the angle and duration of sunlight at a given latitude.
Apply the guide
After equal rainfall, a soil plot has lower outlet flow. What measurement helps distinguish infiltration from pooling?Reveal explanation
Measure soil moisture below the surface, and check pooled water separately. The outlet alone does not distinguish all paths.
Sites at matching north and south latitudes change daylight in opposite directions. Which feature of the tilt model fits?Reveal explanation
One hemisphere tilts toward the Sun while the other tilts away, giving the sites different daylight durations.
Turn the idea into practice.
Apply the rule to a new case, then explain your choice.
Practice this skillSources & authorship
Sources support scientific principles. Practice scenarios and teaching examples are original.
Original OpenExam guide
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USGS Surface Runoff and the Water CycleNASA Space Place What Causes the Seasons