SOUND1

How is transmission of sound affected by the kind of material?

Why is it hard for us to hear sound during daytime when we are in an open field?

How does temperature affect the speed of sound?

ACTIVITY
FASTER SOUND… IN HOTTER OR COOLER?
(20 mins)

PRESENTATION OF OUTPUTS

Sound travels through air by causing air molecules to vibrate.
The temperature of the air can affect how sound waves travel.

During day time, The ground heats up, causing the air near the surface to become warmer than the air above. This cause sound wave to bend upwards, away from the ground, making it harder for us to hear distant sounds. At night, the grounds cools down, and the air near the surface of the earth becomes cooler than above, which can cause sound waves to bend downwards, making distant sounds more audible.

Draw

What is the speed of sound at 35^o C?

Draw

What is the speed of sound at -20^o C?

Multiple Choice

1.    Speed of sound is unaffected by the temperature of the medium.

• TRUE

• FALSE

Multiple Choice

2.   With the increase in temperature, kinetic energy increases causing increase in vibrations and faster speed of sound.

• TRUE

• FALSE

Multiple Choice

3.   At which temperature will sound waves travel fastest?

• 5 °C

• 10 °C

• 20 °C

• 40 °C

Multiple Choice

3.   At which temperature will sound waves travel the slowest?

• 5 °C

• 10 °C

• 20 °C

• 40 °C

Create wind chimes made of indigenous materials.