Newton's Laws Simulator
Explore all three of Newton's Laws with interactive simulations. Calculate net force and acceleration with friction for the Second Law, visualize action-reaction pairs, and understand inertia through the First Law. No signup, runs entirely in your browser.
Newton's Second Law — F = ma
The net force on an object equals its mass times its acceleration. Direction of acceleration matches net force direction.
Newton's Laws Tips
Finding friction coefficient
Typical coefficients of kinetic friction: ice on ice ≈ 0.03, rubber on wet road ≈ 0.4, rubber on dry road ≈ 0.7, wood on wood ≈ 0.3. Static friction is always higher than kinetic.
Negative acceleration
If the applied force is less than the friction force, the net force and acceleration are both negative. This means the object decelerates if already moving, or cannot move if at rest (static friction holds it).
Third law pairs
Remember: the action and reaction forces always act on different objects. The Earth pulls you down with gravity — you pull the Earth up with exactly the same force. The Earth barely moves because it is vastly more massive.
Inertia in daily life
When a car accelerates, your body appears to be pushed back — this is inertia resisting the change in velocity. A seatbelt applies the forward force needed to accelerate you along with the car.
Frequently Asked Questions
What are Newton's three laws of motion?
First law (Inertia): an object stays at rest or in uniform motion unless acted on by a net force. Second law (F=ma): net force equals mass times acceleration. Third law (Action-Reaction): every action has an equal and opposite reaction on a different object.
What is the friction force formula used here?
The kinetic friction force is calculated as f = μ × m × g, where μ is the coefficient of kinetic friction, m is mass, and g = 9.81 m/s². Typical values: rubber on concrete μ ≈ 0.7, wood on wood μ ≈ 0.3, ice on ice μ ≈ 0.03.
What happens when friction force equals applied force?
When friction equals the applied force, net force is zero and the object either stays at rest (static case) or moves at constant velocity (kinetic case). The simulator shows this as zero acceleration.
Does the second law work in both directions?
Yes. If the net force is negative, the acceleration is negative (deceleration or acceleration in the opposite direction). The simulator shows negative acceleration when friction exceeds the applied force.
What is a real-world example of Newton's Third Law?
A rocket expels gas backward at high speed (action). The gas pushes the rocket forward (reaction). The forces are equal in magnitude, opposite in direction, but act on different objects — the rocket and the gas.
Is my data stored?
No. All simulations run locally in your browser. No data is sent to any server.