Summary of GCSE Physics Revision "Required Practical 1: Specific Heat Capacity"

Summary of GCSE Physics Revision "Required Practical 1: Specific Heat Capacity"

This video explains a practical experiment designed to determine the Specific Heat Capacity of a material, specifically Vegetable Oil, which is a common required practical in GCSE Physics.

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Main Ideas and Concepts

• Specific Heat Capacity Definition:
  The amount of energy required to raise the temperature of 1 kilogram of a substance by 1°C.
• Purpose of the Practical:
  To experimentally determine the Specific Heat Capacity of Vegetable Oil.

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Methodology / Step-by-Step Instructions

1. Preparation:
   • Place a Beaker on a balance and zero the balance.
   • Add Vegetable Oil to the Beaker and record its mass.
2. Setup:
   • Insert a Thermometer and an Immersion Heater into the oil.
   • Record the initial temperature of the oil.
   • Wrap the Beaker with insulating foam to minimize heat loss to the surroundings.
3. Energy Input:
   • Connect the Immersion Heater to a power pack and a Joulemeter.
   • The Joulemeter measures the total electrical energy (in joules) supplied to the Immersion Heater.
4. Heating:
   • Leave the setup running for about 30 minutes to allow the oil’s temperature to rise sufficiently.
5. Final Measurements:
   • Record the final temperature of the oil.
   • Record the total energy supplied as indicated by the Joulemeter.
6. Calculation:
   • Use the formula:
     Change in thermal energy = mass × Specific Heat Capacity × temperature change
   • Rearranged to find Specific Heat Capacity:
     c = ΔE / (m × Δθ)
     where
     ΔE = energy supplied (J),
     m = mass (kg),
     Δθ = temperature change (°C).
7. Example Calculation:
   • Mass = 0.95 kg
   • Initial temperature = 20°C
   • Final temperature = 75°C
   • Energy supplied = 87,258 J
   • Temperature change = 55°C
   • Specific Heat Capacity c = 87258 / (0.95 × 55) = 1670 J/kg°C

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Sources of Error and Improvements

• Heat Loss to Surroundings:
  Some thermal energy escapes from the Beaker into the air.
  Improvement: Use better insulation with lower thermal conductivity.
• Incomplete Energy Transfer:
  Not all energy from the Immersion Heater transfers to the oil.
  Improvement: Ensure the Immersion Heater is fully submerged.
• Thermometer Reading Errors:
  Manual reading may be inaccurate.
  Improvement: Use an electronic temperature probe.
• Uneven Heat Distribution:
  Thermal energy might not spread evenly through the oil.
  Improvement: Stir the oil during heating.
• Other minor inaccuracies may exist but these are the main factors.

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Summary Conclusion

By following this practical method and addressing potential errors, students can accurately determine the Specific Heat Capacity of a material. This practical is commonly tested in GCSE exams.

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Speakers / Sources Featured

• Primary Speaker: The presenter from FreeScienceLessons.co.uk (unnamed)
• No other speakers or external sources are explicitly mentioned.

Category

Educational

Video