Forces and Vectors
Forces are interactions that can change the motion of an object. Vectors have both magnitude and direction. Understanding how forces combine as vectors is essential for analysing motion and equilibrium.
What You Need to Know
Key Concept Diagram
A force is a push or pull that can change an object's speed, direction, or shape
Vectors have both magnitude (size) and direction, unlike scalars which have magnitude only
Forces can be added as vectors; when all forces balance, the net force is zero (equilibrium)
Friction, gravity, normal force, and applied force are common forces in everyday situations
Key Vocabulary
Vector
A quantity with both magnitude and direction (e.g. force, velocity, displacement)
Scalar
A quantity with magnitude only (e.g. speed, mass, temperature)
Net force
The overall force on an object after all forces have been added as vectors
Equilibrium
The state when all forces acting on an object are balanced and the net force is zero
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
A box is pushed with 30 N to the right and 10 N friction acts to the left. What is the net force?
Question 2
Which of the following is a vector quantity?
Question 3
A book rests on a table with zero acceleration. What can you conclude about the forces?
Key Concepts Summary
- ●A force is a push or pull that can change an object's speed, direction, or shape
- ●Vectors have both magnitude (size) and direction, unlike scalars which have magnitude only
- ●Forces can be added as vectors; when all forces balance, the net force is zero (equilibrium)
- ●Friction, gravity, normal force, and applied force are common forces in everyday situations