Figure 2 shows an energy transfer diagram for a steam engine. The diagram shows the amounts of energy transferred each second by the steam engine. energy input 2000 J useful energy output 160 J wasted energy (i) Calculate the amount of wasted energy. (ii) Calculate the efficiency of the steam engine. Use the equation efficiency = (useful energy transferred by the steam engine) (total energy supplied to the steam engine) (iii) State what happens to the wasted energy. (iv) Coal is a fossil fuel that is burnt in some steam engines. State two ways that the use of coal might be harmful to the environment. (b) A model train has a mass of 8.0 kg. It travels at a speed of 1.5 m/s. Calculate the kinetic energy of the model train. Use the equation kinetic energy = ½ × mass × (speed)²

GCSE Edexcel Physics Combined Science Energy stores & Transfers: Figure 2 shows an energy transfe

Figure 2 shows an energy transfer diagram for a steam engine - Edexcel - GCSE Physics Combined Science - Question 2 - 2019 - Paper 1

Question 2

Figure 2 shows an energy transfer diagram for a steam engine. The diagram shows the amounts of energy transferred each second by the steam engine. energy input 200... show full transcript

Worked Solution & Example Answer:Figure 2 shows an energy transfer diagram for a steam engine - Edexcel - GCSE Physics Combined Science - Question 2 - 2019 - Paper 1

Step 1

Calculate the amount of wasted energy.

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Answer

To find the wasted energy, subtract the useful energy output from the energy input:

\text{wasted energy} = \text{energy input} - \text{useful energy output} = 2000 \text{ J} - 160 \text{ J} = 1840 \text{ J}

Step 2

Calculate the efficiency of the steam engine.

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Answer

Using the efficiency formula:

\text{efficiency} = \frac{\text{useful energy transferred by the steam engine}}{\text{total energy supplied to the steam engine}} = \frac{160 \text{ J}}{2000 \text{ J}} = 0.08

To express this as a percentage:

\text{efficiency} = 0.08 \times 100\% = 8\%.

Step 3

State what happens to the wasted energy.

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The wasted energy is typically lost to the surroundings as heat, which can contribute to thermal pollution. Some of it may also be dissipated through friction or other inefficiencies in the system.

Step 4

State two ways that the use of coal might be harmful to the environment.

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Answer

Burning coal releases carbon dioxide (CO₂) and other greenhouse gases, contributing to climate change.
The combustion of coal can produce sulfur dioxide (SO₂) and nitrogen oxides (NOx), leading to air pollution and acid rain.

Step 5

Calculate the kinetic energy of the model train.

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Answer

Using the kinetic energy formula:

\text{kinetic energy} = \frac{1}{2} \times \text{mass} \times \text{(speed)}^2 = \frac{1}{2} \times 8.0 \text{ kg} \times (1.5 \text{ m/s})^2\n$$ Calculating this gives:

\text{kinetic energy} = \frac{1}{2} \times 8.0 \times 2.25 = 9 , \text{J}.

Figure 2 shows an energy transfer diagram for a steam engine - Edexcel - GCSE Physics Combined Science - Question 2 - 2019 - Paper 1

Worked Solution & Example Answer:Figure 2 shows an energy transfer diagram for a steam engine - Edexcel - GCSE Physics Combined Science - Question 2 - 2019 - Paper 1

Calculate the amount of wasted energy.

Calculate the efficiency of the steam engine.

State what happens to the wasted energy.

State two ways that the use of coal might be harmful to the environment.

Calculate the kinetic energy of the model train.

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