A free body diagram (FBD) is a visual representation used to show all the forces acting on an object. To determine if an object is accelerating based on its FBD, you can follow these steps:
- Identify the Forces: Look at the diagram and identify all the forces acting on the object, including gravitational force, normal force, friction, tension, and any applied forces.
- Check for Net Force: Add up all the forces vectorially. This means taking into account both the magnitude and direction of each force. If the sum of the forces, also known as the net force, is greater than zero, then the object is accelerating.
- Direction of Acceleration: The direction of the net force will also indicate the direction of the acceleration. According to Newton’s second law (F = ma), the acceleration occurs in the direction of the net force.
- Equilibrium Check: If the object is in equilibrium, meaning all forces are balanced (the net force is zero), then it is not accelerating. In this case, the object is either at rest or moving at a constant velocity.
In summary, if you see that the net force acting on the object in the free body diagram is not zero, the object is accelerating. Conversely, if all the forces cancel each other out, the object is not accelerating.