Mechanics
Drop on the Moon
Watch everything fall in slow motion under weaker Moon gravity.
Drop on the Moon — interactive Mechanics simulation. Watch everything fall in slow motion under weaker Moon gravity. Free browser-based virtual physics lab with live SI measurements and a guided tutorial.
Gravity on the Moon
Gravitational acceleration depends on the planet. On the Moon, g is about 1.6 m/s² — much smaller than on Earth.
The same objects take longer to fall and hit the ground more gently under lunar gravity. Comparing Earth and Moon presets highlights that g is a property of the gravitational environment, not the object.
- g_Earth ≈ 9.8 m/s²
- g_Moon ≈ 1.6 m/s²
Investigation brief
Plan the question before you open the lab
The brief mirrors the prerendered page: driving question, competing predictions, variable roles, governing laws, setup, analysis and extension prompts remain visible and in this order.
Driving question
On the Moon, a 1 kg ball and a 6 kg ball are released together from the same height, in a vacuum with no air resistance. Which one speeds up faster as it falls?
Predictions to weigh
- The heavier (6 kg) ball speeds up faster
- Both balls speed up at exactly the same rate
- The lighter (1 kg) ball speeds up faster
Variable roles
What you set:
- Mass (m) (kg)
- Elapsed Time (t) (s)
What you measure:
- Velocity (vy) (m/s)
- Momentum (p) (kg·m/s)
How the investigation runs
- Open the Moon Drop preset. Note the two balls: a light one (1 kg) and a heavy one (6 kg), released together under the Moon's gravity (g = 1.6 m/s²).
- Select each ball in turn and set its mass in the properties panel to match the Mass column of the data table below before each run.
- Release both balls, pause the sim at the elapsed time listed in the Time column, and read the ball's downward velocity (vy) from the probe.
Governing equation
Momentum — p = m·v
Momentum p = mv combines an object's mass and velocity into a single quantity — even though the light and heavy balls share the same fall speed at a given time, the heavier ball carries much more momentum.
Kinetic Energy — KE = ½·m·v²
KE = ½mv² grows with the square of speed and directly with mass — so two balls hitting the ground at the same speed still carry very different amounts of kinetic energy if their masses differ.
What the printable worksheet asks students to work out
- Using your recorded vy and mass values, compute the momentum p = mv for each row. Show your work.
- Compare rows 1 and 2 (same time, different mass) and rows 2 and 3 (same mass, different time). What does each comparison tell you about how velocity depends on mass versus time?
Where this shows up beyond the lab
- Explain, using F = ma and weight = mg, why a heavier ball does not fall faster on the Moon — even though gravity pulls on it with more force.
- If this same experiment were done on Earth by dropping a feather and a bowling ball through air, would your data table look the same? Why or why not?
- AP Physics 1 — Unit 1: Kinematics
- AP Physics C: Mechanics — Unit 1: Kinematics
- IB Physics — A.1 Kinematics
- General High School Physics — Motion & kinematics
- NGSS High School Physics — Forces and Newton's second law
- Middle School Physical Science — Gravity between objects
- Middle School Physical Science — Stored (potential) energy
- Welcome to Moon Drop
- Select the ball
- Press Play
- Gentle lunar fall
- Open the data
- You did it!
Open the interactive simulation to build the scene, press Play, and explore with live measurements and a guided tutorial.