Practicals

• What can you investigate using the described experiment?

  The link between force and extension
• What is the formula to calculate weight in the experiment?

  W = mg
• What should you do if a mass causes a bigger increase in extension than previous masses?

  You should use smaller masses
• What are the steps to measure the extension of a spring in the experiment?

  1. Measure the natural length of the spring.
  2. Add a mass and measure the new length.
  3. Calculate the extension as the change in length.
  4. Repeat until you have at least 8 measurements.
• What does a straight line on the force-extension graph indicate?

  There is a linear relationship between force and extension
• What happens to the relationship between force and extension when the line begins to bend?

  The relationship becomes non-linear
• How can you check if the deformation of the spring is elastic or inelastic?

  Remove the masses and check if the spring returns to its previous extension
• What law does the experiment investigating mass and force relate to?

  Newton's 2nd law
• What is the procedure to investigate how mass affects acceleration?

  1. Set up the trolley with a card for the light gate.
  2. Connect the trolley to a string over a pulley.
  3. Add masses to the trolley one at a time.
  4. Record the average acceleration for each mass.
• What does the weight of the book provide in the experiment?

  The accelerating force
• How do you keep the total mass of the system the same while changing the force?

  Transfer masses from the trolley to the hook
• What are the key steps to investigate the effect of force on acceleration?

  1. Start with masses on the trolley.
  2. Transfer masses to the hook to increase force.
  3. Keep the total mass constant.
  4. Record average acceleration for each force.
• How many measurements should you aim to collect in the spring extension experiment?

  No fewer than 8 measurements
• What does the gradient of the straight line on the force-extension graph represent?

  The spring constant (k)
• What happens if you exceed the limit of proportionality in the spring experiment?

  The spring will stretch more for each unit increase in force
• What is the speed of sound in air?

  330 m/s
• What is the procedure to measure the speed of water ripples using a lamp?

  1. Use a signal generator with a ripple tank.
  2. Create water waves at a set frequency.
  3. Use a lamp to project shadows of waves.
  4. Measure distance between shadow lines.
  5. Divide by 10 to find wavelength.
  6. Use $v =$$f\lambda$ to calculate wave speed.
• Why is it important to ensure the size of the waves’ shadows is the same size as the waves?

  To accurately measure the wavelength
• What does the distance between shadow lines represent?

  One wavelength
• How can you find the wavelength if measuring distance is difficult?

  Take a photo of the shadows and ruler
• What is the formula to calculate wave speed?

  $v =$$f\lambda$
• What is the procedure to measure the speed of waves on strings?

  1. Set up equipment with a signal generator.
  2. Adjust frequency until a clear wave appears.
  3. Measure length of multiple half wavelengths.
  4. Calculate mean half wavelength and double it.
  5. Use $v =$$f\lambda$ to find wave speed.
• What is the best way to measure the wavelength of waves on a string?

  Measure multiple half wavelengths
• What factors affect the frequency needed for waves on a string?

  Length of string and mass used
• What are the characteristics of sound waves, ripples, and waves on strings?

  • They are model waves.
  • They are easy to work with.
  • They can be measured and analyzed.
• What is a Leslie cube made of?

  Watertight metal, e.g., aluminium
• What is the procedure to investigate IR emission with a Leslie cube?

  1. Place Leslie cube on a heat-proof mat.
  2. Fill with boiling water.
  3. Measure temperature of each face.
  4. Use an infrared detector at a set distance.
  5. Record IR radiation detected from each face.
  6. Repeat for reliability.
• What should you expect when measuring IR radiation from different surfaces of a Leslie cube?

  More IR from black than white surfaces
• Why is it important to repeat the Leslie cube experiment?

  To ensure results are reliable
• What safety precautions should be taken during the Leslie cube experiment?

  Don't move the cube when full of boiling water
• What is the relationship between radiation and temperature in the context of the Leslie cube?

  • Different surfaces emit IR radiation differently.
  • Temperature affects the amount of radiation emitted.
  • Black surfaces emit more IR than shiny surfaces.