- Forces between objects
- A force can change the shape of an object, or change its state of rest, or its motion.
- Equal and Opposite forces
- Whenever two objects push or pull on each other, they exert equal and opposite forces on each other. For example- a boxer who punches his opponent with a force of 100N,experiences a reverse force of 100N from his opponent.
- The unit of force is the newton (N)
- In the mud
- A car stuck in the mud can be very hard to shift. A tractor is useful; the force of the rope on the car is equal and opposite to the force of the car on the rope. The force of the ground on the tractor needs to be greater than the force of the mud on the car. These two forces are not necessarily equal because the objects are not the same
- Friction in action
- The driving force (motive force) on a car is the force which makes it move. This force is due to friction between the ground and the tyres and friction acts where the tyre is in contact with the ground. These two forces are equal and opposite to each other.