Home > Subjects > Physics > Level 3 > 3.3 Wave systems > Key tips
- Subject: Physics
- AS: AS90520
- Level: 3
- Credits: 4
- External
Physics 3.3 Demonstrate understanding of wave systems
Key tips
- Understand that a physics problem involves a process(es) to find a physical quantity.
- Show all working of your calculations including any rearrangement of formulae.
- Be aware of the appropriate use of significant figures and units. You may use both negative index (for example, m s–2) and slash notation (for example, m/s2) when writing units. However, the examination paper will supply data using negative index notation.
- In the examination, make sure you read all questions carefully. That way, you are clear about what is being asked for, and what information is given.
- Understand that Doppler shift is dependent only on velocity, not distance.
- Know when to use (-) or (+) in the Doppler formula.
- Do not confuse the speed of sound with the speed of light.
- Recognise that all electromagnetic radiations (light, radio, microwaves, etc) travel at the speed of light.
- Understand and be able to describe the unique properties of a diffraction grating (compared with a double-slit).
- Understand the difference between closed and open pipes in forming harmonics, and be able to use the relationship between pipe length and wavelength in calculations.
- Recognise that nλ=dx/L is an approximation based on sine ≈ tangent, and is only accurate for small angles (that is, when L is much larger than x). nλ=dsinθ is a more accurate formula.
