# Interaction of Forces (Frictional Force, Gravitational Force, elastic Spring force)

Forces are essential components that are integral to understanding the behaviour of objects. Forces are responsible for the motion, speed, and direction of objects. Here, we will explore the interaction of three fundamental forces: frictional force, gravitational force, and elastic spring force. These forces are crucial in the study of physics and have practical applications in our daily lives.

## Essential Takeaways:

• Frictional force opposes motion between two objects.
• The force of gravity increases with the mass of the objects.
• The force exerted by an elastic spring is directly proportional to the amount of stretching or compression.

## Learning Objectives:

• Define frictional force, gravitational force, and elastic spring force.
• Understand how these forces affect the behaviour of objects.
• Identify practical applications of these forces in daily life.

## Core ideas:

• Forces are essential components that affect the behaviour of objects.
• There are three fundamental forces – frictional force, gravitational force, and elastic spring force.
• Frictional force opposes motion between two surfaces in contact.
• Gravitational force is the force of attraction between two objects with mass.
• Elastic spring force is the force exerted by a stretched or compressed spring.
• These forces are crucial in the study of physics and have practical applications in our daily lives.

## Points to Remember:

• Force is a push or pull that can change the motion or direction of an object.
• Frictional force is the force that opposes motion between two objects in contact.
• Gravitational force is the force of attraction towards the centre of the earth, for an object having mass.
• Elastic spring force is the force exerted by a spring that is compressed or stretched.

## Practices:

• Conduct experiments to demonstrate the effects of frictional, gravitational, and elastic spring forces.

## Key Questions:

### What is frictional force, and how does it affect motion?

Frictional force is the force that opposes motion between two objects. It affects motion by making it harder for objects to move and causing them to slow down.

### What is the gravitational force, and how does it keep us on the ground?

Gravitational force is the force of attraction towards the centre of the earth, for an object having mass. It keeps us on the ground by pulling us towards the centre of the Earth.

### What is elastic spring force?

Elastic spring force is the force exerted by an elastic spring when it is stretched or compressed.

### How can frictional force be reduced?

Here are some methods to reduce frictional force:
1. Using lubricants
2. Polishing the surface
3. Selecting a material with smoother surface
4. Using rollers or ball bearings
5. Reducing contact area

### What are the effects of force?

Force can cause an object to start moving, stop moving, or change its direction or speed.