Experimnts

Question 1

How does rainbow desk bells make different sound?

Answer 1

Frequency of vibration of bells are different
Produce sound of different pitches
(thickness and length)

Question 2

Why does the windup music box’s tune turn louder, when placed on plastic board?

Answer 2

Vibration of plastic board.
Molecules (of plastic board) sets air particles to vibration.
More molecules, transmission of energy more efficient

Question 3

Plastic ruler?

Answer 3

1. Place plastic ruler on the bench.
2. Press the ruler firmly with one hand, exposing 10cm of the free end over the edge
3. Bend the free end and let go
   » Ruler moves up and down quickly, producing a sound
4. Repeat but with longer ruler length
   » Ruler moves in same vibration direction but slower, with a lower pitch

Question 4

Tap the tuning fork gently on rubber stopper.

Answer 4

Hold the tuning fork close to your ear.
Sound produced is low pitched and quiet.

Question 5

Strike the tuning fork hard on the rubber stopper.

Answer 5

Hold the tuning fork close to your ear.
Sound produced is louder.

Question 6

Tap the tuning fork gently on rubber stopper, but

Answer 6

touch prongs with fingernails.
Prongs are vibrating.

Question 7

What does tuning forks part 1 tell us?

Answer 7

We need more energy to set a higher amount of molecules in motion.

Question 8

Tuning fork–> fill a plastic basin with water. Tap the tuning fork on a rubber stopper…

Answer 8

Immediately touch the water surface with tuning fork.
- Ripples form on the water surface
- The tuning fork is vibrating

Question 9

Tuning fork - place a vibrating fork gently on hollow wooden box and listen.

Answer 9

A sound is produced.

Question 10

Place three different vibrating tuning forks together onto the wooden box.

Answer 10

Sounds are produced in harmony.

Question 11

Tuning forks are classified as

Answer 11

Acoustic resonator

Question 12

Tuning forks affecting one another’s natural resonance

Answer 12

Sympathetic resonance.
If frequency is correct, the vibrating sound waves produced by one tuning fork
Will create similar vibration in a nearby tuning fork of same frequency.

Question 13

Tuning fork, elbow -> hand -> ear

Answer 13

Strike a tuning fork on rubber stopper and touch the handle of it to student’s elbow.
1. Sound is heard
2. Sound vibrations will travel up the arm and be heard
3. HENCE Sound can travel through solid.