A student investigated how much energy from the Sun was incident on the Earth's surface at her location - AQA - GCSE Physics - Question 12 - 2018 - Paper 1
Question 12
A student investigated how much energy from the Sun was incident on the Earth's surface at her location.
She put an insulated pan of water in direct sunlight and me... show full transcript
Worked Solution & Example Answer:A student investigated how much energy from the Sun was incident on the Earth's surface at her location - AQA - GCSE Physics - Question 12 - 2018 - Paper 1
Step 1
Choose the most appropriate resolution for the thermometer used by the student.
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Answer
The most appropriate resolution for the thermometer used by the student is 0.1 °C. This resolution allows for precise temperature measurements that can capture small changes in the water temperature.
Step 2
Write down the equation which links energy transferred, power and time.
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Answer
The equation that links energy transferred (E), power (P), and time (t) is:
E=Pimest
Step 3
Calculate the mean power supplied by the Sun to the water in the pan.
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Answer
To find the mean power, we use the equation:
P = rac{E}{t}
Given the energy transferred to the water is 1050 J and the time taken is 5 minutes (which is 300 seconds), we have:
P = rac{1050 ext{ J}}{300 ext{ s}} = 3.5 ext{ W}
Step 4
Calculate the mass of water the student used in her investigation.
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Answer
We can calculate the mass of water using the formula:
E=mimescimesheta
where E is the energy transferred (1050 J), c is the specific heat capacity of water (4200 J/kg °C), and θ is the temperature change (0.6 °C). Rearranging this equation for mass (m) gives:
m = rac{E}{c imes heta}
Substituting the values, we have:
m = rac{1050}{4200 imes 0.6} = 0.417 ext{ kg}
Step 5
Give one reason why.
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Answer
One reason the student’s results can only be used as an estimate of the mean power is that energy transfer to the surroundings through the insulation may vary. This means that not all the energy from the Sun is transferred to the water.
