Practicals

• What is the purpose of a ripple tank?

  To observe features of water waves
• What equipment is used in a ripple tank setup?

  A shallow tray of water and a vibrating bar
• How does the vibrating bar in a ripple tank work?

  It creates waves across the water surface
• What happens when light shines through the water in a ripple tank?

  It produces an image of the waves on paper
• How can you measure the wavelength of water waves in a ripple tank?

  By measuring the distance of 10 wavelengths
• What is the total distance measured for 10 wavelengths if it equals 26 centimeters?

  0.26 meters
• How do you find the wavelength from the total distance of 10 wavelengths?

  Divide the total distance by 10
• What is the calculated wavelength of the waves?

  0.026 meters
• How is frequency defined in the context of water waves?

  Number of waves passing a point each second
• What method is suggested for measuring frequency accurately?

  Count waves in 10 seconds and divide by 10
• What is the frequency if 24 waves pass in 10 seconds?

  2.4 Hertz
• What is the wave equation used to determine wave speed?

  Wave speed = frequency × wavelength
• What is the wave speed if the frequency is 2.4 Hertz and the wavelength is 0.026 meters?

  $0.0624 \text{ m/s}$
• What is another method to determine wave speed in a ripple tank?

  Measure time for a wave to travel the tank
• Why might results differ when measuring wave speed by different methods?

  Due to measurement errors in timing
• What should you be able to describe by the end of the video?

  How to measure wavelength, frequency, and speed
• What apparatus is used to measure waves in a solid?

  A string attached to a vibration generator
• What keeps the string taut in the experiment?

  A hanging mass
• What does the signal generator do in the experiment?

  It changes the frequency of vibration
• What is a standing wave?

  A wave pattern formed by resonance
• In which instruments do we find standing waves?

  Stringed musical instruments like guitars
• How do you measure the wavelength of a standing wave?

  Measure total length from bridge to generator
• How do you convert 21.5 centimeters to meters?

  0.215 meters
• What is the wave equation used in the experiment?

  Wave speed = frequency × wavelength
• If the frequency is 10 Hertz and the wavelength is 0.215 meters, what is the wave speed?

  2.15 meters per second
• What happens to the standing wave when the frequency increases?

  The standing wave changes to more half wavelengths
• How do you calculate the wavelength from the total length and number of half wavelengths?

  Divide total length by half wavelengths, then multiply by 2
• What is the calculated wavelength when the total length is 0.215 meters and there are three half wavelengths?

  0.143 meters
• If the frequency used to create the wave is 15 Hertz, what is the wave speed?

  2.15 meters per second
• What does the wave speed depend on in the experiment?

  Tautness of the string and mass per centimeter
• What is the formula to calculate the wavelength from the total length and number of half wavelengths?

  Wavelength = (Total length / Half wavelengths) × 2
• What are the steps to calculate the wave speed in the experiment?

  1. Measure the frequency from the signal generator.
  2. Measure the wavelength using the total length and half wavelengths.
  3. Use the wave equation: Wave speed = frequency × wavelength.
• What are the key features of standing waves in solids?

  • Formed by resonance
  • Can have multiple half wavelengths
  • Depend on string tautness and mass
• What should you remember for the exam regarding standing waves?

  • Calculate wavelength using total length and half wavelengths.
  • Understand the relationship between frequency, wavelength, and wave speed.
  • Recognize the role of string tension and mass.
• What is the main objective of the practical described in the video?

  Investigate infrared radiation absorption and emission
• Why can't the human eye see infrared radiation?

  Infrared radiation is outside the visible spectrum
• What is a Lesley's cube used for?

  To measure infrared emission from surfaces
• How many different surfaces does a Lesley's cube have?

  Four different surfaces
• What are the four surfaces of a Lesley's cube?

  Shiny metallic, white, shiny black, matte black
• What is the first step in using a Lesley's cube for the experiment?

  Fill the cube with hot water