Physics

Question 1

travelling sounds

Answer 1

All sounds require a medium (ie, particles) to travel through, therefore sounds cannot pass through a vacuum (such as space).

Question 2

So, do sounds travel faster in solids, liquids or gases?

Answer 2

The closer the particles are to each other, the faster the sound will travel. Therefore sounds travel fastest in solids, then in liquids.

Question 3

wave energy

Answer 3

Waves are a means of transfer-ring energy – this is done in a repeating cycle. The particles vibrate, or
oscillate, back and forth.

Question 4

names one or two types of wave

Answer 4

two types of wave:
- transverse
- longitudinal

Question 5

whats happens in a transverse wave?

Answer 5

In a transverse wave, the vibrations occur at right angles to the direction of energy transfer.

Question 6

what happens in a longitudinal wave?

Answer 6

In a longitudinal wave, the vibrations occur in the same direction as the direction of energy transfer.

Question 7

frequency

Answer 7

All types of wave have a frequency. This is a measure of how many waves pass a particular point every second.The unit for frequency is the hertz (Hz)

Question 8

superposition

Answer 8

The principle of superposition shows what happens when two waves meet after approaching each other.

Question 9

whats is constructive interference?

Answer 9

Constructive interference occurs when two waves travelling in
opposite directions reinforce each other.

Question 10

what is destructive interference

Answer 10

occurs when a peak and a trough travelling in opposite directions partially or fully
cancel each other out

Question 11

what does a loudspeaker do?

Answer 11

A loudspeaker has a cone that vibrates with the same frequency as the sound being played. An electrical signal passing through an electromagnet causes the
vibration, which agitates air particles, creating a sound wave.

Question 12

what does a microphone do?

Answer 12

A microphone has a small diaphragm that vibrates when a sound wave (moving air from our voice) hits it. This generates a small electrical signal, which passes into an amplifier – this makes the sound louder when
it is played through the loudspeaker.

Question 13

how is it related into making music

Answer 13

Each voice and instrument has its own unique series of tones that give the waves have distinct shapes.
This is partly because the sound wave is made in different ways…

Question 14

How much hertz can we hear?

Answer 14

We are not able to hear sounds below 20Hz (subsonic), or sounds above 20000Hz (ultrasonic).

Question 15

hearing damage

Answer 15

The loudness of a sound can be measured in decibels (dB).
The louder the sound, and the longer you are exposed to a loud sound, the greater the chance of hearing damage.This could include damage to the eardrum, bones or the hairs in the cochlea, which may not be repaired.

Question 16

thermal equilibrium

Answer 16

Thermal energy always transfers from where there is more, to where there is less.

Question 17

what is heat?

Answer 17

Heat is a type of energy (normally referred to as thermal energy).

Question 18

what is temperature

Answer 18

Temperature is a measure of how intense the heat is (‘hotness’), and can be measured using a thermometer; the unit is
degrees Celsius (°C).

Question 19

what happens in thermal conduction?

Answer 19

When the particles nearest the heat source gain energy, and they vibrate more…

Question 20

conduction

Answer 20

Conduction cannot occur in liquids or gases, since the particles are too far apart to transfer energy by collision.

Question 21

convection

Answer 21

Convection is the method of heat transfer in liquids and gases (but not solids), as the particles are able to move and flow past each other.

Question 22

convection currents

Answer 22

The heated particles can then displace the cooler particles at the top of the container.

Question 23

infrared radiation

Answer 23

All objects emit waves of infrared energy (a bit like light, but we can’t see it); this process is known as radiation.