Free Fall & Motion Graphs
Drop or throw an object and watch position and velocity graphs build in real time.
About the Free Fall & Motion Graphs
Free interactive free fall simulator. Change height, gravity and starting velocity, then watch the object fall while position-time and velocity-time graphs draw live. Built for physics, the free fall & motion graphs runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Drop or throw an object and watch position and velocity graphs build in real time. Use it to explore physics ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Free Fall & Motion Graphs
- Use the controls to change Starting height, Starting velocity (up is +), Gravity. The simulation reacts instantly.
- Pick an option such as Moon, Mars, Earth, Jupiter to switch modes or load an example.
- Press "Drop", "Pause" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Drop from 50 m and read the fall time.
- Throw upward at 15 m/s and find the peak.
- Switch to the Moon.
- Compare the position and velocity graphs.
Key ideas you can learn
- Under gravity alone, velocity changes by g every second, so the velocity-time graph is a straight line.
- The position-time graph of free fall is a parabola.
- Fall time from rest is t = √(2h / g), and it does not depend on mass.
Where this is used in the real world
Free fall is the basis of skydiving physics, drop-tower rides, crash tests and the design of parachutes and space capsules.
Who is this simulation for?
Physics students in middle school, high school and first-year university, teachers who want a quick demonstration for the projector, and anyone revising for exams. It works well for flipped classrooms because students can explore before the lesson.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
Do heavier objects fall faster?
Not without air resistance. All objects accelerate at the same rate g, so a heavy and a light object dropped together land together.
What does the slope of a velocity-time graph mean?
The slope is acceleration. In free fall it is constant and equal to g.
Is the Free Fall & Motion Graphs free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Free Fall & Motion Graphs work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.