Best examples of gravity and mass relation experiments you can actually do

Real-world examples of gravity and mass relation experiments

When teachers ask for examples of gravity and mass relation experiments, they usually mean one of two things:

• Does a heavier object fall faster than a lighter one?
• How does mass change the forces involved in motion under gravity?

The good news: you can test both questions with simple setups. The best examples include classic drop tests, ramp experiments, and timing-based measurements that make the math visible instead of just repeating the myth that “heavy things fall faster.”

Below are several real examples that scale from kitchen-table science to high school and intro-college labs.

Classic drop test: comparing fall times of different masses

One of the most famous examples of gravity and mass relation experiments is the simple vertical drop test. Think of the (probably exaggerated) story of Galileo dropping balls from the Leaning Tower of Pisa. Whether or not he actually did it that way, the core idea is easy to reproduce.

You take two objects with very different masses but similar shapes and sizes—for instance, two metal spheres of the same diameter but different materials (steel vs. aluminum). Hold them at the same height, drop them at the same time, and listen for the impacts.

What you expect:

• In a vacuum, both objects experience the same gravitational acceleration, about 9.8 m/s² near Earth’s surface.
• In air, if their shapes and areas are similar, they still hit the ground almost simultaneously because air resistance is nearly the same.

This experiment highlights a key distinction:

• Mass does not change gravitational acceleration (in a uniform field, ignoring air).
• Mass does change weight, since weight = mass × gravitational acceleration.

Students often think “heavier means faster.” Watching two very different masses land together is one of the best examples of how gravity contradicts that intuition.

For deeper background on free-fall motion and acceleration, the Physics Classroom provides a clear overview of kinematics and gravity that aligns well with this setup: https://www.physicsclassroom.com

Feather and coin (or paper) drop: revealing air resistance

Another widely used example of a gravity and mass relation experiment is the feather-and-coin style drop. In a perfect vacuum, a feather and a coin fall the same way. In air, they absolutely do not.

You can approximate this experiment using:

• A flat sheet of paper and a coin
• Or a crumpled ball of paper and the same coin

First, drop a flat sheet of paper and a coin from the same height. The coin reaches the ground first. Then repeat with the paper tightly crumpled into a ball. Now the paper ball lands much closer in time to the coin.

What you’re actually testing:

• The gravitational pull on each object depends on mass.
• The air resistance depends heavily on shape and cross-sectional area.

This example of a gravity and mass relation experiment shows that mass alone does not set fall time; the interaction of gravity with the environment (air) is just as important. The comparison between flat and crumpled paper provides one of the cleanest real examples of how drag competes with gravity.

For a more advanced classroom, you can connect this to terminal velocity and drag forces, which are covered in many introductory college physics courses and open resources like MIT OpenCourseWare: https://ocw.mit.edu

Atwood machine: mass, acceleration, and tension in a gravitational field

If you want a more quantitative example of gravity and mass relation experiments, an Atwood machine is a classic. Two masses hang on either side of a pulley, connected by a string. When the masses are unequal, the system accelerates.

Setup:

• Two hanging masses, m₁ and m₂, with m₂ > m₁
• A low-friction pulley
• A motion sensor or stopwatch and meter stick

You release the system from rest and measure:

• The acceleration of the masses
• The time it takes for a mass to move a known distance

From Newton’s second law, the theoretical acceleration is:

a = (m₂ − m₁)·g / (m₁ + m₂)

Here’s what this experiment reveals:

• Gravity provides the driving force (difference in weight: (m₂ − m₁)g).
• The total mass (m₁ + m₂) resists acceleration because of inertia.

This is one of the best examples of how mass both creates gravitational force (through weight) and opposes changes in motion (through inertia). By changing the masses and recording the acceleration, students can test how closely their data match the predicted values, and even estimate g.

Many high school and college lab manuals, including those from universities like the University of Colorado or MIT, feature Atwood machines as standard experiments to explore Newton’s laws and gravity together.

Inclined plane experiments: separating weight and normal force

Inclined plane setups are underrated examples of gravity and mass relation experiments because they slow everything down. Instead of dropping objects, you let them slide or roll down a ramp.

Basic idea:

• Place a cart or block on a low-friction track or wooden ramp.
• Adjust the angle of the incline.
• Measure the time it takes the cart to travel a known distance.

The component of gravitational force along the ramp is:

F‖ = m·g·sin(θ)

The acceleration along the ramp is:

a = g·sin(θ)

Notice how the mass cancels out in the acceleration expression. That means:

• A heavier cart and a lighter cart, on the same ramp angle, accelerate at the same rate (if friction is negligible), even though the heavier cart has a larger force acting on it.

This is a powerful example of how mass affects force but not acceleration in uniform gravity, echoing the drop tests but in a more controlled, measurable way. Many 2024–2025 physics classrooms use motion sensors or photogates to track position and velocity along the ramp, turning a simple demo into a data-rich experiment.

For more on inclined planes and forces, the Khan Academy physics section gives a clear breakdown of components of weight and acceleration: https://www.khanacademy.org

Pendulum timing: mass independence and gravitational acceleration

A pendulum is one of the most elegant examples of gravity and mass relation experiments because it looks like mass should matter, but it doesn’t—at least for small swings.

You can build a pendulum with:

• A string and a small metal washer
• The same string and a heavier metal nut

Measure the period (time for one full back-and-forth swing) for different masses while keeping the length of the string and the swing amplitude small and consistent.

The theoretical period for a simple pendulum is:

T = 2π·√(L/g)

Mass does not appear in this formula. The result:

• A heavier bob and a lighter bob of the same length have nearly the same period.

Students often expect the heavier pendulum to swing “harder” and therefore faster. Timing multiple swings with a stopwatch quickly shows that the period is controlled by length and gravity, not mass. This is one of the best examples of a gravity and mass relation experiment that directly challenges intuition while giving clean, repeatable numbers.

Spring scale vs. balance scale: weight, mass, and gravity

Not all examples of gravity and mass relation experiments involve motion. Some of the most informative ones are static, comparing how devices measure mass and weight.

You can set up a simple comparison:

• Use a spring scale (which measures force) to read weight.
• Use a balance scale (which compares masses) to read mass.

Place the same object on both devices and record:

• The weight in newtons or pounds on the spring scale.
• The mass in grams on the balance.

Then, if possible, repeat the measurement in a location with slightly different gravitational acceleration—for example, a tall building’s basement vs. top floor won’t show a measurable change, but the thought experiment helps:

• Weight changes if g changes (on the Moon, Mars, or other planets).
• Mass does not change with location.

This experiment reinforces the idea that:

• Mass is a measure of how much matter is present.
• Weight is the gravitational force on that mass.

NASA’s education pages often use astronaut examples to explain this difference—an astronaut has the same mass on Earth and the Moon, but a very different weight because lunar gravity is weaker. A good starting point is NASA’s Solar System Exploration education section: https://solarsystem.nasa.gov

Smartphone sensor experiments: modern 2024–2025 examples

Modern classrooms increasingly use smartphones as lab tools, and they provide some of the most accessible 2024–2025 examples of gravity and mass relation experiments.

Most smartphones have built-in accelerometers. With a physics or sensor app installed, you can:

• Measure the apparent acceleration when the phone is at rest (it reads about 1 g upward because it senses the normal force resisting gravity).
• Record acceleration during free fall in a safe, short drop onto a cushion or inside a padded box (the reading approaches 0 g while in free fall).

Now pair the phone with different attached masses—for instance, tape the phone to a light cardboard box, then to a heavier wooden block, and slide them down a smooth ramp. The recorded acceleration along the ramp stays roughly the same, even though the total mass of the system changes.

This modern example of a gravity and mass relation experiment brings the same physics you see in inclined planes and drop tests into a digital format. It also connects nicely to real-world technology, since accelerometers are used in everything from car crash sensors to fitness trackers.

Organizations like the American Association of Physics Teachers (AAPT) regularly publish classroom-tested smartphone experiments, reflecting a clear trend toward integrating everyday devices into physics labs.

Large-scale real examples: satellites, astronauts, and planetary gravity

Classroom setups are great, but some of the best real examples of gravity and mass relation experiments come from space missions and satellite measurements.

A few cases worth mentioning:

• Satellite orbits: The acceleration of a satellite in orbit depends on the mass of the planet or moon it orbits and its distance from the center, not on the satellite’s own mass. A small CubeSat and a massive communications satellite at the same orbital radius share the same orbital period.
• Astronaut training: NASA uses drop towers and parabolic flights to create short periods of microgravity. In those conditions, objects of different mass float side by side, illustrating that in free fall, mass does not change the experience of weightlessness.
• Planetary comparisons: NASA’s data on surface gravity for different planets show how the same mass has different weights on Earth, Mars, and Jupiter. Mass is constant; gravitational acceleration changes with the planet’s mass and radius.

These large-scale examples of gravity and mass relation experiments are not just demonstrations; they are baked into the way space agencies design missions, from choosing rocket thrust to planning landings.

For accurate planetary gravity values and mission examples, NASA’s fact sheets and education resources are a reliable reference: https://nssdc.gsfc.nasa.gov

Putting it together: patterns across all these experiments

Looking across all these examples of gravity and mass relation experiments, a few patterns show up again and again:

• In a uniform gravitational field and ignoring air resistance, all objects accelerate the same way, no matter their mass.
• Mass still matters because it sets weight (force due to gravity) and inertia (resistance to acceleration).
• When you bring in real-world effects—air resistance, friction, tension, normal forces—mass affects how those forces play out, even though the basic gravitational acceleration is the same.

From simple drop tests to Atwood machines, pendulums, ramps, smartphone sensors, and satellite motion, these experiments all echo the same core idea: gravity treats mass in a very specific, predictable way. That’s why these are the best examples for teaching students how to separate everyday intuition from actual physics.

FAQ: examples of gravity and mass relation questions

Q: What are some easy classroom examples of gravity and mass relation experiments?
Simple drop tests with balls of different mass, paper vs. coin drops, and short pendulums with different bobs are all easy examples. Inclined planes with carts of different mass are also practical for middle and high school.

Q: Can you give an example of an experiment that shows mass does not affect gravitational acceleration?
A clean example of this is dropping two spheres of the same size but different mass from the same height and timing the fall. If air resistance is similar, they hit the ground together, showing that acceleration is independent of mass.

Q: Which experiments show that weight depends on gravity as well as mass?
Spring scale vs. balance scale comparisons are clear examples. The balance measures mass only, while the spring scale reads weight, which changes if gravitational acceleration changes (for example, on another planet or in a thought experiment about the Moon).

Q: How do modern tools improve these classic gravity experiments?
Smartphones with accelerometers and motion sensors let you record detailed acceleration data during drops, ramps, or pendulum swings. That turns classic demonstrations into quantitative experiments with graphs and numerical analysis.

Q: Are there real examples outside the classroom that show the relation between gravity and mass?
Yes. Satellite orbits, astronaut experiences in microgravity, and differences in surface gravity between Earth and other planets are all real-world examples of gravity and mass relations that space agencies like NASA measure and use in mission planning.