Start equally
Both balls begin at rest at the same height.
Gravity on Other Worlds
Release two balls from equal heights and compare their motion under different surface gravities without air.
Grades 3–5 · Physics
Your goal
Compare Moon with Earth from the same 10 m height. Advance the shared clock until both balls land.
Reduced motion is on. The controls still update the scene.
Shared time 0.0 s. Earth landing time 1.43 s. Earth landing time 1.43 s.
m
Both balls start at rest, have the same release height, and share one clock. Constant surface gravity and no air resistance isolate gravity. Ball size is enlarged independently of the 10 pixels per metre height scale. Changing the world or height restarts the drop.
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Learn with Gravity on Other Worlds
Gravity on Other Worlds gives elementary students a fair way to compare falling motion. Choose the Moon, Mars, Earth, Venus, or Mercury, set one release height, and advance a clock shared by both drop chambers. An Earth reference ball starts from exactly the same height as the comparison ball. With air resistance removed, differences in landing time come from surface gravity. Read the height remaining and calculated landing times, then repeat at a new height to explain why weaker gravity means a longer fall.
What to look for
Advance together
Use the half second control to move both balls through the same time interval.
Compare landings
A smaller surface gravity produces a longer fall time from the same height.
For teachers and curious learners
Compare fall time under different gravity using one height and one shared clock. Ask students to predict what will happen, change one setting, and explain what they observe. Learn gives a starting point. Practice and Challenge offer new goals with the same scene.
Constant approximate surface gravities, release from rest and no air resistance. The Earth reference always uses the same height and elapsed clock as the chosen world.