Forces and Motion: Newton's Second Law
Push a cart with different forces and friction and see acceleration, speed and net force.
Drag pullers from the bottom tray onto the rope, blue on the left and red on the right, then press Go! The bigger the net force, the faster the cart accelerates. Try friction on ice, wood and sand.
About the Forces and Motion: Newton's Second Law
Free forces and motion: newton's second law. Push a cart with different forces and friction and see acceleration, speed and net force. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for physics, the forces and motion: newton's second law 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.
Push a cart with different forces and friction and see acceleration, speed and net force. 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 Forces and Motion: Newton's Second Law
- Use the controls to change Ground, Cart mass. The simulation reacts instantly.
- Pick an option such as Ice, Wood, Sand, Force arrows to switch modes or load an example.
- Press "Go!", "Pause", "Return cart" 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
- Push with 300 N on ice and on sand.
- Double the mass.
- Push, then set the force to zero and watch on ice.
Key ideas you can learn
- Net force = mass × acceleration.
- Friction opposes motion.
- Without friction, a moving cart keeps moving.
- A bigger mass accelerates less for the same force.
Where this is used in the real world
Vehicle design, safety and sport all depend on F = ma and friction.
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
What is net force?
The sum of all forces on an object. It decides the acceleration.
Why does the cart stop on sand?
Friction is large, so the net force is opposite the motion and slows it.
Is the Forces and Motion: Newton's Second Law 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 Forces and Motion: Newton's Second Law 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.