Photo AI

A man monitors how much money he spends on electricity - Edexcel - GCSE Physics - Question 6 - 2015 - Paper 1

Question icon

Question 6

A-man-monitors-how-much-money-he-spends-on-electricity-Edexcel-GCSE Physics-Question 6-2015-Paper 1.png

A man monitors how much money he spends on electricity. He uses a device which calculates the cost of electrical energy used. He connects his 2.9 kW electric kettle ... show full transcript

Worked Solution & Example Answer:A man monitors how much money he spends on electricity - Edexcel - GCSE Physics - Question 6 - 2015 - Paper 1

Step 1

Calculate the current in the kettle element.

96%

114 rated

Answer

To calculate the current, we use the formula:

I=PVI = \frac{P}{V}

where:

  • II is the current in amperes (A),
  • PP is the power in watts (W), which is 2.9 kW or 2900 W,
  • VV is the voltage in volts (V), which is 230 V.

Substituting the values in:

I=2900230=12.61 AI = \frac{2900}{230} = 12.61 \text{ A}

Thus, the current in the kettle element is approximately 12.61 A.

Step 2

Calculate the length of time for which the kettle has been switched on during the week.

99%

104 rated

Answer

To determine the time the kettle has been switched on, we first find the total energy consumed using the cost. The total cost is 97 p, and the cost per kWh is 17 p, so:

Total Energy (kWh)=97 p17 p/kWh=5.71 kWh\text{Total Energy (kWh)} = \frac{97 \text{ p}}{17 \text{ p/kWh}} = 5.71 \text{ kWh}

Next, to find the time in hours for which the kettle was on, we use the formula:

Time (h)=Energy (kWh)P(kW)\text{Time (h)} = \frac{\text{Energy (kWh)}}{P (kW)}

where:

  • PP is 2.9 kW.

Substituting the values in:

Time=5.712.9≈1.97 hours\text{Time} = \frac{5.71}{2.9} \approx 1.97 \text{ hours}

Thus, the kettle has been switched on for approximately 1.97 hours.

Join the GCSE students using SimpleStudy...

97% of Students

Report Improved Results

98% of Students

Recommend to friends

100,000+

Students Supported

1 Million+

Questions answered

;