Resolving a force - Higher
Two forces can be added together to find a The single force that could replace all the forces acting on an object, found by adding these together. If all the forces are balanced, the resultant force is zero.. A single force can be resolved (broken down) into two One of two forces, at right angles to each other, that can be added together to form a resultant force. at right angles to each other.
In the diagram of a toy trailer below, when a child pulls on the handle, some of the 5 newton (N) force pulls the trailer upwards away from the ground and some of the force pulls it to the right.
Vector diagrams can be used to resolve the pulling force into a horizontal component acting to the right and a vertical component acting upwards.
Vector diagrams
Draw a right-angled triangle to scale, in which each side represents a force. Try to choose a simple scale, for example 1 cm = 1 N. For the toy trailer example above, draw:
- a line representing the 5 N force at 37掳
- a horizontal line ending directly below the end of the first line
- a vertical line between ends of the two lines
- arrow heads to show the direction in which each force acts
Measure the lengths of the horizontal and vertical lines. Use the scale for the first line to convert these lengths to the corresponding forces.
When combined, the two component forces have the same effect as the single force. In this example, the child's pulling force.