Resultant forces


Parallelogram H

Parallelogram H ANS



Inclined plane

Mystery for pupils to solve. Resultant forces


A number of forces acting on an object may be replaced by a single force that has the same effect as all the original forces acting together. This single force is called the resultant force.

Students should be able to calculate the resultant of two forces that act in a straight line.

(HT only) Students should be able to:

  • describe examples of the forces acting on an isolated object or system
  • use free body diagrams to describe qualitatively examples where several forces lead to a resultant force on an object, including balanced forces when the resultant force is zero.
  • (HT only) A single force can be resolved into two components acting at right angles to each other. The two component forces together have the same effect as the single force.
  • (HT only) Students should be able to use vector diagrams to illustrate resolution of forces, equilibrium situations and determine the resultant of two forces, to include both magnitude and direction (scale drawings only).

WS 1.2 Use a variety of models such as representational, spatial, descriptive, computational and mathematical to solve problems, make predictions and to develop scientific explanations and understanding of familiar and unfamiliar facts.

MS 4a -Translate information between graphical and numeric form

MS 5a -Use angular measures in degrees

MS 5b - Visualise and represent 2D and 3D forms including two dimensional representations of 3D objects