Describe what happens to the wasted energy - Edexcel - GCSE Physics Combined Science - Question 3 - 2016 - Paper 1
Question 3
Describe what happens to the wasted energy.
(b) Explain one way the experiment can be improved to reduce the amount of wasted energy.
(c) The initial mass of the w... show full transcript
Worked Solution & Example Answer:Describe what happens to the wasted energy - Edexcel - GCSE Physics Combined Science - Question 3 - 2016 - Paper 1
Step 1
Describe what happens to the wasted energy.
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Answer
The wasted energy usually dissipates into the surroundings, primarily as heat. This can occur through various mechanisms such as conduction, convection, and radiation. As heat escapes, it reduces the overall efficiency of the system, meaning not all the energy supplied by the heater is used to boil the water.
Step 2
Explain one way the experiment can be improved to reduce the amount of wasted energy.
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Answer
One way to improve the experiment and reduce wasted energy is to insulate the beaker with materials like foam or thermal blankets. This would limit heat loss to the environment, ensuring that more energy is used for boiling the water rather than being lost to the surroundings.
Step 3
Use an equation from the formula sheet to calculate the specific latent heat of the water.
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Answer
To calculate the specific latent heat (L) of the water, we can use the formula:
L=mQ
where Q is the thermal energy transferred, and m is the mass of the water that changed state.
The change in mass of the water is:
Mass lost=0.72kg−0.60kg=0.12kg
Now, substitute the values into the equation:
L=0.12kg270000J=2250000J/kg
Thus, the specific latent heat of the water is 2250000 J/kg.