Physics Assessment 2

• What types of waves are we constantly bombarded by?

  Light, sound, and heat waves
• What are the four common properties of all waves?

  Wavelength, frequency, amplitude, and speed
• How is wavelength (λ) defined?

  Distance from one peak to the next
• In what unit is wavelength measured?

  Metres (m)
• What is the unit of frequency?

  Hertz (Hz)
• What does frequency (f) measure?

  Number of waves passing a point per second
• What is amplitude (A) in wave terms?

  Height of the wave from peak to trough
• How is amplitude measured for sound waves?

  In decibels (dB)
• If a wave has a frequency of 500 Hz, what is its wavelength if speed is 1 m/s?

  $\lambda =$$\frac{v}{f} =$$\frac{1 \text{ m/s}}{500 \text{ Hz}} =$$0.002 \text{ m}$
• What is the equation for wave speed?

  Speed = Frequency × Wavelength
• What is the formula for wave speed in symbols?

  $v =$$f\lambda$
• What happens to the wavelength when a source moves towards an observer?

  The wavelength becomes shorter
• What is the Doppler Effect?

  Change in wavelength due to relative motion
• How does the frequency of a wave change when the source moves towards you?

  The frequency increases and wavelength decreases
• What are electromagnetic (EM) waves?

  Transverse waves with different properties
• How are EM waves grouped?

  By their wavelength and frequency
• What mnemonic helps remember the order of colors in EM waves?

  Richard Of York Gave Battle In Vain
• What are radio waves primarily used for?

  Mainly for communications
• What is the wavelength range of radio waves?

  Longer than about 10 m
• How do radio waves travel around the Earth?

  They bend around the Earth's curvature
• What is the primary use of microwaves?

  Satellite communication and heating food
• What is the wavelength of microwaves?

  Around 10 cm
• How do microwaves heat food?

  They cause water molecules to vibrate
• What does infrared radiation depend on?

  The temperature of the object
• What is infrared radiation also known as?

  Heat radiation
• How do optical fibers transmit light signals?

  By carrying communication signals at high speeds
• What are two uses of optical fibers?

  Telephones and broadband internet
• What is the purpose of X-rays?

  To image internal structures of objects
• How do X-rays work in medical imaging?

  They are directed through the patient
• What is the advantage of gamma radiation in sterilization?

  It kills microorganisms without heat
• What is a potential danger of EM radiation?


  It can permanently damage cells
• How does frequency affect the danger of EM radiation?

  Higher frequency means more energy and harm
• What is the relationship between frequency and energy in EM radiation?

  Higher frequency correlates with higher energy