Required practical

• Method fir acceleration: Draw a series of straight lines, each 20 cm apart, perpendicular to the edge of the bench. Attach the car to the string at one end, with the other end running across the bench pulley. Attach the weight stand to the loose end of string. Hold the weight of the pulley, so it doesn’t pull the car but so that the string is fully extended. Release the weight stand (allowing it to fall) and begin the timer. Stop timing when the car hits the pulley at the other end of the bench.
• Investigating the relationship between force and extension for a spring

  1. Set up clamp stand, bosses, and clamps

  2. Place heavy weight on clamp stand

  3. Attach meter rule under spring, with top at 0 point

  4. Attach wooden splint pointer to bottom of spring, keep horizontal

  5. Read unstretched length of spring

  6. Add 1 Newton weight, read new pointer position

  7. Continue adding 1 Newton weights, read pointer positions

  8. Calculate extension for each weight by subtracting unstretched length

  9. Plot extension vs weight graph
• Graph of extension vs weight

  • Straight line through origin
  • Linear relationship between force and extension
  • Elastic deformation - extension returns to 0 when weight removed
  • Inelastic deformation - over-stretching, extension remains when weight removed
• Linear relationship


  Straight line graph, extension directly proportional to weight
• Nonlinear relationship


  Curved graph, extension not directly proportional to weight
• Elastic deformation


  Extension returns to 0 when weight removed
• Inelastic deformation


  Extension remains when weight removed, spring over-stretched
• Limit of proportionality


  Point on graph where relationship becomes nonlinear
• Spring constant is the same for any part of the graph as long as the limit of proportionality is not exceeded
• Investigating the acceleration of an object


  1. Hold the toy car at the starting point

  2. Let go of the car

  3. Record the time the car passes each distance marker

  4. Repeat the experiment several times with decreasing mass on the end of the string

  5. Keep the overall mass of the object the same
• Object


  • Toy car, string, and mass on the end of the string
• Acceleration of the object

  Proportional to the force applied
• Force applied


  Weight of the mass on the end of the string
• Acceleration of the object

  Proportional to the mass on the end of the string
• Investigating how varying the mass of the object affects the acceleration produced by a constant force

  1. Keep the force constant using a 100 gram mass

  2. Attach a mass to the toy car

  3. Repeat the experiment increasing the mass attached to the toy car
• Acceleration of the object

  Inversely proportional to the mass of the object
• You'll find plenty of questions on this required practical in the revision workbook
• Ripple tank


  A shallow tray of water with a vibrating bar that creates waves across the surface of the water
• Ripple tank


  • Has a lump below the tank and a sheet of white paper, when light shines through the water it produces an image of the waves on the paper
• Measuring wavelength


  Place a ruler on the paper, freeze the image of the waves, measure the distance between one wave and 10 waves, divide by 10 to find one wavelength
• Measuring frequency


  Place a timer next to the paper, count the number of waves passing a point in 10 seconds, divide by 10 to find the frequency in Hertz
• Measuring wave speed


  1. Use the wave equation: wave speed = frequency in Hertz x wavelength in meters

  2. Select a wave and measure the time it takes to move the length of the tank, divide the distance traveled by the time taken
• Measuring wave speed using the two methods may give slightly different results due to measurement errors
• Measuring wavelength, frequency and speed of waves in a solid


  1. Set up apparatus with string, vibration generator, and hanging mass

  2. Observe standing wave pattern

  3. Measure total length of standing wave

  4. Calculate wavelength by dividing total length by number of half-wavelengths and multiplying by 2

  5. Read frequency from signal generator

  6. Calculate wave speed using wave equation (wave speed = frequency x wavelength)
• Standing wave


  • Formed due to resonance effect
  • Not required to explain how standing waves or resonance happen in exam
• Standing waves found in


  • Stringed musical instruments (e.g. guitar)
• Wave equation


  Wave speed = frequency x wavelength
• Increasing frequency of standing wave

  Changes standing wave pattern to have more half-wavelengths
• Wave speed of string does not depend on frequency or wavelength, but on tautness of string and mass per centimeter
• In exam, could be shown any standing wave pattern and asked to calculate wavelength
• Plenty of questions on this required practical in the revision workbook
• Investigating how much infrared radiation is absorbed or radiated by different surfaces

  1. Observe glowing coals emitting visible light

  2. Understand that hot surfaces emit infrared radiation

  3. Use a Leslie's cube with 4 different surfaces (shiny metallic, white, shiny black, matte black)

  4. Fill Leslie's cube with hot water

  5. Point infrared detector at each surface and record infrared emission

  6. Ensure same distance between Leslie's cube and detector for repeatability

  7. Observe that matte black surface emits most infrared, followed by shiny black, white, and shiny metallic emits least

  8. Use a thermometer with black bulb if no infrared detector available, but less resolution

  9. Use infrared heater with two metal plates (one shiny metallic, one matte black)

  10. Attach pins to plates with Vaseline

  11. Switch on heater and time how long it takes for pins to fall off due to Vaseline melting

  12. Observe that pin falls off matte black plate first, as matte black absorbs more infrared than shiny metallic
• Infrared radiation


  • Hot surfaces emit infrared
  • Infrared cannot be seen by the human eye
• Leslie's cube


  • 4 different surfaces: shiny metallic, white, shiny black, matte black
  • Used to measure infrared emission from different surfaces
• Infrared detector


  • More sensitive than thermometer, can detect small differences in infrared emission
• Thermometer with black bulb

  • Less resolution than infrared detector, may not detect small differences in infrared emission
• Infrared heater and metal plates

  • Used to measure infrared absorption by different surfaces (shiny metallic, matte black)
  • Pins attached with Vaseline to measure time for Vaseline to melt
• Matte black surfaces are much better at emitting and absorbing infrared than shiny metallic surfaces
• Infrared tends to be reflected from shiny metallic surfaces
• This is a required practical, so the details shown need to be learned