Practicals etc

• What is specific heat capacity?

  It is the amount of energy needed to raise the temperature of 1 kg of a substance by 1°C.
• Why do different materials have different specific heat capacities?

  Because more energy needs to be transferred to the thermal energy stores of some materials than others.
• How much energy is needed to warm 1 kg of water by 1°C?

  4200 J
• What happens to materials that require a lot of energy to warm up?

  They also transfer a lot of energy when they cool down and can store a lot of energy.
• What is the equation that links energy transferred to specific heat capacity?

  ∆E = mc∆θ
• What does each symbol in the equation ∆E = mc∆θ represent?

  ∆E is change in thermal energy, m is mass, c is specific heat capacity, and ∆θ is temperature change.
• What are the steps to investigate specific heat capacities of solids?

  1. Measure the mass of the block.
  2. Wrap it in an insulating layer.
  3. Insert thermometer and heater.
  4. Measure initial temperature and set power supply to 10 V.
  5. Turn on power and start stopwatch.
  6. Record temperature and current every minute for 10 minutes.
  7. Calculate power supplied using P = VI.
  8. Calculate energy transferred using E = Pt.
  9. Plot graph of energy transferred against temperature.

  10. Find gradient to determine specific heat capacity.
• How can you investigate the specific heat capacity of liquids?

  • Place heater and thermometer in an insulated beaker filled with a known mass of liquid.
  • Follow similar steps as for solids to measure temperature changes.
• How do you find the final temperature of water after energy transfer?

  Use the formula: final temperature = initial temperature + (E / (m * c)).
• What is the relationship between current and potential difference in ohmic conductors?

  The current is directly proportional to the potential difference at a constant temperature.
• What is the formula for resistance in terms of voltage and current?

  R = V / I
• How does the resistance of a filament lamp change with temperature?

  Resistance increases with temperature as the filament heats up.
• How does the I-V characteristic of linear components differ from non-linear components?

  Linear components have a straight line I-V characteristic, while non-linear components have a curved I-V characteristic.
• What are the steps to investigate adding resistors in series?

  1. Find at least four identical resistors.
  2. Build the circuit with one resistor.
  3. Measure potential difference and current.
  4. Calculate resistance using R = V ÷ I.
  5. Add another resistor in series and repeat measurements.
  6. Plot graph of number of resistors against total resistance.
• What are the steps to investigate adding resistors in parallel?

  1. Build the circuit with one resistor.
  2. Measure total current and calculate resistance.
  3. Add another resistor in parallel and repeat measurements.
  4. Plot graph of number of resistors against total resistance.
• What happens to total resistance when resistors are added in series?

  Total resistance increases as more resistors are added in series.
• What happens to total current when resistors are added in parallel?

  Total current increases as more resistors are added in parallel.
• What does density measure?

  Density measures the mass of a substance per unit volume.
• How does the arrangement of particles affect density?

  Denser materials have particles that are more closely packed together.
• What is the formula for calculating density?

  Density (kg/m³) = mass (kg) / volume (m³)
• How do you find the density of a solid object?

  Measure mass and volume, then use the density formula.
• How do you find the density of a liquid?

  Measure the mass of the liquid and its volume, then calculate density.
• What is internal energy related to?

  It is related to the average kinetic energy of the particles.
• What happens to the temperature when the average kinetic energy of particles increases?

  Things seem hotter when the average kinetic energy of the particles increases.
• What is the relationship between internal energy and temperature?

  Internal energy is stored energy related to the kinetic energy of particles.
• What is the formula to find density?

  Density = mass / volume
• How do you find the density of an object using its mass and volume?

  Plug the object's mass and volume into the density formula.
• What does 1 ml equal in cubic centimeters?

  1 ml = 1 cm³
• What does taking an average of calculated densities provide?

  A value for the density of the liquid.
• What is density related to in terms of particles in a substance?

  How tightly packed the particles are.
• What is internal energy in terms of particles?

  • Average kinetic energy of particles
  • Stored energy in kinetic and potential energy
• What happens to the average kinetic energy of particles when things seem hotter?

  The average kinetic energy of the particles increases.
• What effect does heating have on the kinetic energy of particles?

  Heating increases the kinetic energy, causing particles to move faster.
• What does changing state of a material not affect?

  It does not change the mass of the material.
• How can a change of state be observed?

  Through changes in density.
• What happens to a solid when it is heated?

  • Change in temperature
  • Change in state to liquid or gas
• What is the relationship between temperature change and particle kinetic energy?

  The change in temperature relates to how the average kinetic energy of the particles is changing.
• What is the first step in measuring mass accurately?

  • Place an empty container on the scale
  • Read off the mass
• How should you measure the mass of a liquid?

  Zero the balance with an empty beaker before pouring in the liquid.
• What is the most common tool to measure length?

  A ruler.