Force is a push or a pull.
The SI Unit of force is Newton(N).
Oxford English dictionary describes force as strength or energy as an attribute of physical action or movement.
A force acts acts in a particular direction and have the following effects:
Effects of force
(i) change the state of motion of a body.
A body that is not moving can be set in motion when a force is applied on it and a moving body will stop when force is applied against it the opposite direction to it’s motion.
a moving body can increase its speed if a force is a applied on it in the direction of it’s motion and it’s motion can be reduced when an opposing force is acting against it’s motion. For example friction force reduces motion of an object dragged on a flat surface.
(ii) Distorts or changes shape of an object.
For example a force applied on a glass causes it to crack. When force is applied on an elastic material, it expands. A plastic bottle will change shape when force is applied on it. Similarly, a car that meet with an accident will have a bad shape.
(iii) causes object to turn or changes direction.
when a force is applied on one end of the object when it is fixed from another point, the body tends to change direction. The change of direction from a fixed point is usually referred to as the turning effect of force. The figure below illustrates a spanner that turns about a fixed point in order to tighten or loose a nut.
Describing force
Force is also described as the source of energy which changes body’s state of motion, direction or shape. Large forces causes large effects on bodies and small forces has less significant effects on bodies.
Force always acts towards specific direction and so it is a vector quantity as it has both magnitude and direction
Force in diagrams is represented by a line with an arrow showing the direction in which it acts.
Types of forces
- Gravitational force
- Tensional forces
- Frictional forces
- Magnetic force
- Electric force
- Centripetal force
- Cohesive and adhesive forces
- surface tension
- Molecular force
- Upthrust force
- Nuclear forces
- Electrostatic force
Related Topics
- Vector Addition
- Upthrust forces
- The Archimedes’ principle
- Magnetic effect of electric current
- Isaac Newton
- Equilibrium and center of gravity