Have you ever watched a farmer in a village using a bullock cart? The bullocks pull the cart forward. The farmer pushes the plough into the soil. When you kick a football, you push it with your foot. When you pull open a drawer, you use force too.
Every push or pull is called a force. Force makes things move, stop, or change direction. But where do we get the strength to push or pull? That strength comes from energy. Let us learn about both!
What is Force?
A force is a push or a pull that can make an object move, stop, change direction, or change shape.
You cannot see force, but you can see what it does. When you squeeze a ball of clay, force changes its shape. When you throw a ball, force makes it move.
Think about it: When Aarav opens a door, does he push or pull? What about when he closes it?
Types of Force
1. Muscular Force: The force we apply using our muscles. Examples: lifting a bucket of water, pulling a rope during tug-of-war, kneading dough for roti.
2. Gravitational Force: The force that pulls everything towards the Earth. This is why a mango falls down from a tree, not up! It is also called the force of gravity.
3. Magnetic Force: The force a magnet uses to attract objects made of iron. A magnet can pull an iron nail towards it without touching it.
4. Frictional Force: The force that slows down or stops moving objects. When you slide on a rough road, friction stops you. Brakes on a bicycle use friction to stop the wheels.
Think about it: Why is it easier to slide on a smooth marble floor than on a rough cement road? Which surface has more friction?
What is Energy?
Energy is the ability to do work. Without energy, nothing can move, grow, or change. We need energy to walk, talk, cook food, and run machines.
Types of Energy
1. Heat Energy: Energy that makes things warm. A burning stove gives heat energy to cook food. The sun gives us heat.
2. Light Energy: Energy that helps us see. The sun, a lamp, and a candle all give light energy.
3. Sound Energy: Energy that we can hear. A drum, a bell, and a veena all produce sound energy.
4. Electrical Energy: Energy from electricity. It runs fans, lights, televisions, and computers in our homes.
Sources of Energy
The Sun is the biggest source of energy. It gives us heat and light. Food gives energy to our body. Fuel (wood, coal, petrol, LPG gas) gives energy for cooking and running vehicles. Wind and water can also produce energy -- windmills in Rajasthan and dams on rivers produce electricity.
| Word | Meaning |
|---|---|
| Force | A push or pull that changes the state of an object |
| Muscular force | Force applied using muscles of the body |
| Gravity | The force that pulls objects towards the Earth |
| Friction | The force that opposes motion between two surfaces |
| Energy | The ability to do work |
| Fuel | A material that is burned to produce heat or energy |
A potter in a village pushes and shapes wet clay on a wheel using muscular force. A washerman pushes clothes against a stone to clean them. A farmer pulls water from a well using a rope and pulley.
During Makar Sankranti, when the thread of a kite breaks, the kite slowly falls to the ground. Raindrops fall from clouds to the earth. A coconut falls from a palm tree. All of this happens because of gravitational force.
A solar cooker uses heat energy from the sun to cook food without fuel. Windmills in Jaisalmer, Rajasthan, use wind energy to produce electricity. Biogas plants in villages use cow dung to produce cooking gas.
A. Fill in the Blanks
B. Multiple Choice Questions
C. Match the Following
| Column A | Column B |
|---|---|
| 1. Bullock pulling a cart | (a) Gravitational force |
| 2. Mango falling from a tree | (b) Electrical energy |
| 3. Fan running in a room | (c) Frictional force |
| 4. Brakes stopping a cycle | (d) Muscular force |
1 -- 2 -- 3 -- 4 --
D. Short Answer
Force Hunt at Home: Walk around your home and find examples of push and pull. Write at least 4 examples in each column.
| Push (Examples) | Pull (Examples) |
|---|---|
Energy Diary: For one day, write down 5 activities you did and the type of energy used for each (heat, light, sound, or electrical).
| Activity | Type of Energy Used |
|---|---|