Science Class 3 - Light Sound-And-Force Notes
Comprehensive study notes for Class 3 - Light Sound-And-Force olympiad preparation
Light, Sound and Force
Welcome to the chapter on Light, Sound and Force for Class 3. In this chapter, you will learn what light, sound, and force are, how they work, and why they are important in our daily life. By the end of this chapter, you will be able to explain how light helps us see, how sound travels, and how force moves things!
Introduction
Light, sound, and force are all around us. We use light to see, sound to hear, and force to move things. Let’s explore how these work!
What is Light?
- Light helps us see things.
- The sun is the main source of light on Earth.
- We also get light from bulbs, candles, and torches.
- Light travels in a straight line.
Uses of Light
- We need light to see during the day and night.
- Plants need sunlight to grow.
- Light helps us read, write, and play.
What is Sound?
- Sound is what we hear.
- We make sound by talking, clapping, or playing music.
- Animals, vehicles, and machines also make sounds.
- Sound travels through air, water, and solids.
Uses of Sound
- We use sound to talk and listen.
- We enjoy music and songs.
- Sounds can warn us, like a bell or a siren.
What is Force?
- Force is a push or pull that moves things.
- We use force to open a door, kick a ball, or lift a bag.
- Force can change the shape or speed of things.
Uses of Force
- Moving objects from one place to another.
- Stopping or slowing down things.
- Changing the direction of moving things.
Fun Activity: Explore Light, Sound, and Force!
- Shine a torch in a dark room and see how things become visible.
- Make different sounds using your hands, voice, or objects.
- Push and pull a toy car to see how force works.
Summary
- Light helps us see, sound helps us hear, and force helps us move things.
- We use light, sound, and force every day.
- They are important for our daily life and activities.
Practice Questions
- Name two sources of light.
- How do we make sound?
- What is force?
- Why do plants need sunlight?
- Give one example of using force at home.
Challenge Yourself
- Draw and label a picture showing light, sound, and force in action.
- List three things you do every day that use force.
Did You Know?
- Light from the sun takes about 8 minutes to reach Earth!
- Some animals can hear sounds that humans cannot.
- Gravity is a force that keeps us on the ground.
Glossary
- Light: What helps us see things.
- Sound: What we hear.
- Force: A push or pull that moves things.
- Gravity: The force that pulls things towards the Earth.
Answers to Practice Questions
- Sun, bulb (any two: candle, torch, etc.).
- By talking, clapping, or playing music.
- A push or pull that moves things.
- To grow and make food.
- Opening a door, lifting a bag, pushing a chair (any example).
Light, sound, and force make our world exciting! Notice them around you every day.