Light, Sound and Force - Class 3 Science - New St. Mery English School

Light, Sound, and Force are three wonderful gifts of nature that help us understand the world around us. From seeing colorful objects, hearing sweet sounds, to pushing and pulling things—these three play an important role in our daily life.

Light helps us to see. Without light, everything would be dark. The Sun, candles, and electric bulbs are sources of light.
Sound helps us to communicate and enjoy music. We hear sounds when something vibrates.
Force is a push or a pull that makes objects move, stop, change shape, or change direction.

In this chapter, students will learn how light, sound, and force work, where they come from, and how they help us in everyday life. This lesson is designed in a fun and simple way so that Class 3 students can easily understand these basic science concepts and enjoy learning. 🌟

Light, Sound and Force - Class 3 Science - New St. Mery English School 

What is Light?

Ans:- Light is a form of energy that helps us see things.

How many types of object on the basis of Light?

Ans:- There are two types of object on the basis of Light.

1- Luminous object

2- Non-Luminous object

What are Luminous Objects?

Ans:- The objects that give us light are called Luminous Objects.

Ex:- sun, bulb, torch and candle etc

How many types of Luminous object?

Ans:- There are two types of luminous object.

1- Natural luminous object

2- Man-made luminous object

What are Natural Luminous objects?

Ans:- Objects that give out light by themselves and are not man-made are called natural luminous objects.

Ex:- sun, stars, fire, lightning, fireflies etc.

What are Man-made luminous objects?

Ans:- The luminous objects that are made by man are called Man-made luminous objects.

Ex:- bulb, torch and candle etc.

What are Non-Luminous object?

Ans:- Objects that cannot give out light by themselves are called non-luminous objects.

Ex:- book, table, chair, moon, ball etc.

What are transparent objects?

Ans:- Some objects that allow light to pass through them easily are called transparent objects.

Ex:- glass, water etc.

What are translucent objects?

Ans:- Objects through which only some light can pass are called translucent objects.

Ex:- Butter paper, frosted glass, thin cloth, oiled paper

What are opaque objects?

Ans:- Some objects that do not allow light to pass through them are called opaque objects.

Ex:- wood, stone etc.

What is shadow?

Ans:- A shadow is a dark patch formed when an object blocks the path of light. It is always formed on the opposite side to the source of light.

Write three conditions that is necessary for the formation of shadow.

Ans:- The three conditions that is necessary for the formation of shadow are

1- A light source

2- An opaque object

3- A surface such as wall, floor, table top etc.

Write three properties of shadow.

Ans:- The three properties of shadow are

1- The shape of shadow is similar to the shape of object

2- The size can be smaller or bigger than the object.

3- Shadow are always black in colour.

What is Sound?

Ans:- Sound is a form of energy that is produced by vibrations and travels through a medium like air, water, or solids as sound waves.

How many types of sound?

Ans:- There are two types of sound.

1- Pleasant sound

2- Unpleasant sound

What is Pleasant Sound?

Ans:- The sound which makes us feel good is called Pleasant Sound.

Ex:- Musical sounds, Chirping of the birds

What is Unpleasant sound?

Ans:- The sound which makes us uncomfortable is called unpleasant sound.

Ex:- Sound of a drill machine, bursting of loud fire crackers, The honking of vehicles

What is noise?

Ans:- The loud and unpleasant sound is called noise. Noise is harmful for our health.

What is Force?

Ans:- Force is a push or pull on an object. It can not be seen or touched. But you can feel it. You can also use it to do many things.

Write four effects of Force.

Ans:- The four effects of force are

1- A force can move an object.

2- It can change the shape of an object

3- It can slow down or stop a moving object.

4- It can change the direction of a moving object.