Unbalanced Force, Inertia, Friction and Momentum

Unbalanced Force:

An unbalanced force is the force that causes a change in the motion of an object. If two forces acting on an object are balanced, then the object will not move. If the forces are unbalanced, then the object will move in the direction of the stronger force. For example, if you push a ball with a force of 5 N to the right and someone else pushes the ball with a force of 3 N to the left, the ball will move to the right because the force to the right is stronger.

Inertia:

Inertia is the tendency of an object to resist changes in its motion. This means that an object at rest will stay at rest, and an object in motion will stay in motion with the same velocity, unless acted on by an unbalanced force. For example, if you roll a ball on a flat surface, it will continue to roll until it hits something or friction slows it down.

Friction:

Friction is the force that opposes motion between two surfaces that are in contact. It is caused by the irregularities in the surfaces that are in contact. There are different methods of reducing friction, such as applying grease or oil to the surfaces, or using ball bearings or rollers to reduce the surface area in contact.

Momentum:

Momentum is the product of an object's mass and velocity. It is a measure of how difficult it is to stop an object that is moving. The rate of change of momentum is equal to the force acting on the object. For example, if a car is traveling at 50 km/h and suddenly stops, the momentum of the car changes from 1,000 kg*m/s to 0 kg*m/s in a very short time. This means that there must have been a large force acting on the car to bring it to a stop.