3 (a) The power of a car engine is measured in watts, W - Edexcel - GCSE Physics - Question 3 - 2018 - Paper 1
Question 3
3 (a) The power of a car engine is measured in watts, W.
Complete the following sentence by putting a cross (X) in the box next to your answer.
1 watt, W, is the sam... show full transcript
Worked Solution & Example Answer:3 (a) The power of a car engine is measured in watts, W - Edexcel - GCSE Physics - Question 3 - 2018 - Paper 1
Step 1
Complete the following sentence by putting a cross (X) in the box next to your answer.
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Answer
The correct answer is C. 1 watt, W, is defined as 1 joule per second (J/s).
Step 2
(i) Calculate the work done by the driving force over this distance.
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Answer
Work done (W) is calculated using the formula:
W=Fimesd
where:
F = force (1400 N)
d = distance (6.0 m)
Thus, the work done is:
W=1400extNimes6.0extm=8400extJ
Therefore, the work done by the driving force is 8400 J.
Step 3
(ii) Calculate the kinetic energy of the car.
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Answer
The kinetic energy (KE) of an object is calculated using the formula:
KE=21mv2
where:
m = mass (1200 kg)
v = velocity (20 m/s)
Thus, the kinetic energy is:
KE=21×1200extkg×(20extm/s)2=21×1200×400=240000extJ
Therefore, the kinetic energy of the car is 240000 J.