| What are the three main characteristics of vibrations? | Three main characteristics of vibrations are: Amplitude, time period and frequency |
| Name the position of the bob at point 2 | Mean Position |
| Define amplitude. In what unit is it measured in? | The maximum displacement from the mean position to either side is known as amplitude. It’s measured in meters |
| List the characteristics of sound | Pitch, loudness, timbre |
| What is the relation between frequency and time period? | T= 1/f |
| Frequency is measured in | hertz |
| What is the relation between frequency and pitch? | If the frequency is high, the pitch is high and vice versa |
| The shorter the wires, the ______ the frequency | Higher |
| What happens if the air column in a flute has been decreased. | If the air column in the flute has been decreased, the pitch of sound increases. |
| Timbre | The quality of sound |
| Decibel | Unit used for measuring how loud sound is |
| Relation between amplitude and loudness | If the amplitude is high, it would produce a loud sound (and vice versa) |
| Is it possible to hear sound in outer space? Explain. | No, you cannot hear any sounds in near-empty regions of space. Sound travels through the vibration of atoms and molecules in a medium (such as air or water). In space, where there is no medium, sound has no way to travel. |
| Compressions and refractions (explanation) | When sound moves through air, it causes air molecules to move together and/ or move apart. When surrounding air particles have been moved apart, it causes a low pressure area called rarefaction. When air particles move together, it causes an area of high pressure called as compression. |
| Wavelengths (λ) | Distance between two consecutive compressions and rarefactions |
| What happens when the temperature of the medium through which sound travels decreases? | The speed of sound decreases as well |
| Examples of 3 sound absorbing materials | 1. Curtains
2. Gunny bags
3. Asbestos
*Answers may vary |
| Three uses of echoes | 1. In sonars
2. In concert halls
3. Echolocation |
| Uses of sonars | 1. To measure the depth of seas or oceans
2. To locate underwater objects |
