Light, Heat and Sound

What is heat?

• Hot or cold

• The transference of energy from one body to other body

• what is measured using a thermometer

How do we measure temperature?

• With a lamp

• Using lenses

• Touching the body

• Using a thermometer

What is faster, light or sound?

(a)  

When heat increases the volume of a body, it is called...

• Expansion

• Freezing

• Contraction

• Refraction

What picture represents melting?

• 
• 
• 
• 

How does light travel?

• In all directions.

• In a straught line an in one direction.

• In a straight line and in all directions.

• In a straight line.

What type of material permits that light passes through it but it disperses the light?

• Transparent materials.

• Translucent materials.

• Opaque materials.

Write an example of a natural source of light

(a)  

What is refraction?

• It's the change of direction of light when it hits an object

• It's the change of direction of light when it passes from one medium to other medium.

What is sound?

• A form of energy produced by the vibration of bodies

• A form of energy produced by artificial or natural sources.