GCSE Physics: Specific Heat Capacity

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Questions and Answers

What happens to molecules in a material when it is heated?

They gain kinetic energy and move slower.

They lose mass and density decreases.

They gain kinetic energy and start moving faster. (correct)

They become more tightly packed.

Which material has the highest specific heat capacity listed?

Water (correct)

Brick

Copper

Aluminium

What is the specific heat capacity of brick?

385 J/kg°C

129 J/kg°C

4,200 J/kg°C

840 J/kg°C (correct)

Which of the following statements is true regarding lead's specific heat capacity?

Lead warms up and cools down the fastest due to its low specific heat capacity. Signup and view all the answers

What factor does NOT influence the amount of energy needed to change a material's temperature?

The initial temperature of the material Signup and view all the answers

Why are bricks sometimes used in storage heaters?

They store heat for a long time due to their high specific heat capacity. Signup and view all the answers

Which of these materials would require the least amount of energy to raise its temperature?

Lead Signup and view all the answers

How much energy is needed to raise the temperature of 1 kg of water by 1°C?

4,200 Joules Signup and view all the answers

What is the specific heat capacity of water?

4,180 J/kg°C Signup and view all the answers

How is the thermal energy change calculated?

ΔEt = m × c × ΔΘ Signup and view all the answers

If a 0.25 kg mass of water needs to be heated from 20°C to 100°C, what is the temperature change (ΔΘ)?

80°C Signup and view all the answers

For a 2 kg steel block cooling from 300°C to 20°C, how would you calculate the thermal energy lost?

Use the formula ΔEt = m × c × ΔΘ with m = 2 kg, c = 450 J/kg°C, and ΔΘ = 280°C. Signup and view all the answers

What is the required thermal energy to heat 0.25 kg of water from 20°C to its boiling point?

83,600 J Signup and view all the answers

When a 3.5 kg brick is heated with 20,000 J of energy starting from 20°C, what is the increase in temperature?

2.48°C Signup and view all the answers

If a heating system using oil emits energy efficiently, what is its specific heat capacity?

1,800 J/kg°C Signup and view all the answers

What does the specific heat capacity indicate about a material?

The energy needed to raise its temperature Signup and view all the answers

Study Notes

Specific Heat Capacity

Energy transmission occurs through conduction, convection, or radiation, with material conductivity assessed by energy transfer time.
Heating materials increases molecular kinetic energy, resulting in temperature rise; temperature reflects average kinetic energy of molecules.
Different materials require varying energy amounts for temperature changes, influenced by mass, substance (specific heat capacity), and desired temperature change.

Specific Heat Capacity of Materials

Water's specific heat capacity: 4,200 J/kg°C; requires 4,200 Joules to raise 1 kg of water by 1°C.
Other specific heat capacities include:
- Brick: 840 J/kg°C
- Copper: 385 J/kg°C
- Lead: 129 J/kg°C
Lead warms up and cools down quickly due to low specific heat capacity; bricks retain heat longer, ideal for storage heaters.
Common heater fluids: oil (1,800 J/kg°C) and water (4,200 J/kg°C) for effective energy retention.

Calculating Thermal Energy Changes

The thermal energy change can be calculated using the formula: ΔEt = m × c × ΔΘ
- ΔEt = change in thermal energy (J)
- m = mass (kg)
- c = specific heat capacity (J/kg°C)
- ΔΘ = temperature change (°C)

Example Calculation

Sadie’s model steam engine scenario:
- Mass of water: 0.25 kg
- Starting temperature: 20°C, boiling point: 100°C
- Specific heat capacity: 4,180 J/kg°C
- Thermal energy needed:
  - Et = 0.25 × 4,180 × (100 - 20) = 83,600 J

Practice Questions

Calculate thermal energy loss for a 2 kg steel block (c = 450 J/kg°C) cooling from 300°C to 20°C.
Determine the final temperature of a 3.5 kg brick heated from 20°C using 20,000 J (20 kJ).

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Description

Test your understanding of specific heat capacity in the context of energy transfer in physics. This quiz covers key concepts related to conduction, convection, and radiation. Ideal for AQA GCSE students focusing on energy and heating topics.