A force is simply a push or a pull. There are lots of different forces you need to know about:
- Gravity or weight always acting straight downwards
- Reaction force from a surface, usually acting straight upwards
- Electrostatic force between two charged objects. The direction depends on the type of charge (like charges repel, opposite charges attract)
- Thrust or push or pull due to an engine or rocket speeding something up
- Drag or air resistance or friction which is slowing the thing down.
- Lift due to an aeroplane wing.
- Tension in a rope or cable.
Friction is alwsys there to slow things down
- If an object has no force…