Unit 4: Week 1

Question 1

What is a wave?

Answer 1

A disturbance/oscillation that travels through space/time accompanied by a transfer in energy

Question 2

What is a transverse wave?

Answer 2

The displacement is perpendicular to the direction of energy transfer/direction of propagation of the wave

Question 3

What is a longitudinal wave?

Answer 3

Where the displacement is parallel/ in the same plane as the direction of energy transfer/ propagation of wave

Question 4

What is a mechanical/non mechanical wave? What are same examples

Answer 4

Mechanical- matter is needed to transfer energy loose energy as they propagate- sound waves are longitudinal mechanical waves

Non mechanical- no matter needed to transfer energy, generally don’t loose strength as they propagate( unless they interact with materials)- EM waves are transverse non mechanical waves

Question 5

What are earthquakes an example of?

Answer 5

Mechanical waves- techtonic plates shift causing large amounts of energy to release. The resultant vibrations propagate through the earth in the form of S&P waves

S- matter displaces perpendicular to direction of wave propagation/energy transfer
P- matter displaces (expands&contracts) parallel to direction of wave propagation/energy transfer (same plane)

Question 6

How do water waves work?

Answer 6

They are an example of both transverse and longitudinal waves. Water molecules move in a circular motion. In a closed system or at depth (due to compressive forces) the particles don’t propagate in a direction however in an open system, due to wind etc they propagate in a direction in a circular path

Question 7

What are the 5 wave properties?

Answer 7

Displacement- can be +ve -ve as it takes direction into account. This is distance from equilibrium- meters
Amplitude- maximum displacement so is not +ve -ve- meters
Wavelength- distance between two corresponding points on a wave- meters
Time period- time it takes for a complete wave cycle to pass- seconds
Frequency- how many waves pass a second

Question 8

Why are longitudinal waves represented on a wave graph?

Answer 8

Although they look like transverse waves- this is just to made finding wave properties easier, the waves themselves are still longitudinal

Question 9

How would you compare sound waves on a graph?

Answer 9

Amplitude represents volume

Frequency represents pitch

Question 10

How would you compare light on a graph?

Answer 10

Amplitude represents brightness

Frequency represents colour (red/blue shift)

Question 11

What are oscilloscopes?

Answer 11

They display various signal voltages as a function of time- resulting in a digital wave form.
Amplitude- voltage
X axis- time
Multiply these by the base setting