Physics paper 2 practicals

• Water practical

  1. Set up equipment as shown in diagram
  2. pour water 5mm deep
  3. place white sheet underneath
  4. adjust wooden rod so just above water surface
  5. switch on overhead lamp and electric motor
  6. adjust electric motor to produce low frequency waves
  7. adjust height of so that pattern of waves can be seen clearly on white sheet
• How to find the frequency of a wave using a ripple tank

  count the number of ripples that pass a point in 10 seconds

  Divide number of waves by 10
• How to measure wavelength

  measure distance across 10 graps between shadow line

  divide this distance by 10
• How to improve the method of calculating wavelength

  take a photo of the shadows and ruler

  benefit is that waves are not being disturbed
• deeper water means

  longer wavelength because velocity increases and frequency is constant
• Refraction of light

  1. Place a glass box on sheet of paper
  2. Draw around glass box and then remove
  3. Draw a line 90 , normal line
  4. draw a line 20 from normal
  5. replace glass box
  6. using a ray box, point ray of light down drawn line
  7. mark the ray of light emerging from block
  8. remove block and draw refracted
  9. using a protractor measure angle of refraction
  10. repeat the procedure for a rangle of values of angles of incidence
• Source and reason for inaccuracy of refraction of light practical

  source : width of ray

  reason - makes it difficult to judge where centre of ray causes a large uncertainity
• Advantage of use cube

  all surfraces are at the same temp

  more surfaces are tested

  vol and temp of water does not need to be measured