Forces & Free-Body Diagram Tool

The net force on an object equals its mass times its acceleration. When all forces are balanced, the net force is zero and the object is in equilibrium.

If the net force is zero, the object stays at rest or continues moving at constant velocity. A nonzero net force causes acceleration in the direction of the force.

A free-body diagram shows all forces acting on a single object. Each force is drawn as an arrow from the object's center, with length proportional to magnitude and direction showing the force angle.

Common forces include weight, normal, friction, applied, and tension. Drawing an accurate free-body diagram is the first step in solving any force problem.

Friction opposes the direction of motion (or tendency of motion). Kinetic friction acts on moving objects. Static friction prevents motion up to a maximum value.

$N$ is the normal force. The static coefficient is typically larger than the kinetic coefficient for the same surfaces.

On an incline at angle $\theta$, weight decomposes into two components. Along the incline, the component pulls down the slope. Perpendicular to the incline, the component determines normal force.