Free-Body Diagrams & Resolving Forces

What is a free-body diagram?

A diagram showing the forces acting on a single object, represented by arrows.

What should the arrows in a free-body diagram show?

The direction and relative magnitude of each force.

Why are force arrows drawn with different lengths?

To represent different force magnitudes.

How can a free-body diagram show balanced forces?

The forces combine to give a zero resultant force.

Why should forces acting on other objects not be included in a free-body diagram?

It shows only the forces acting on the chosen object.

What does resolving a force mean?

Replacing a force with two perpendicular component forces that have the same combined effect.

Why are forces resolved into components?

To make it easier to analyse forces acting in different directions.

How can a resultant force be determined using a scale drawing?

Draw the vectors head-to-tail and to scale, then measure the resultant from the first vector's start to the last vector's end.

Why must a scale be used in a vector diagram?

To represent the magnitudes of forces accurately.

How can you recognise equilibrium using a vector diagram?

The force vectors form a closed shape, giving zero resultant force.

Why can't you simply add the magnitudes of forces acting at an angle?

Forces are vectors, so their directions must be considered.