The Highway Code gives this information about the stopping distance of a car - Edexcel - GCSE Physics - Question 1 - 2012 - Paper 1
Question 1
The Highway Code gives this information about the stopping distance of a car.
speed = 30 miles per hour
thinking distance = 9 m
braking distance = 14 m
(a) (i) Wha... show full transcript
Worked Solution & Example Answer:The Highway Code gives this information about the stopping distance of a car - Edexcel - GCSE Physics - Question 1 - 2012 - Paper 1
Step 1
What is the stopping distance?
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Answer
The stopping distance is the total distance a vehicle travels from the moment the driver recognizes the need to stop until the car comes to a complete stop. It can be calculated by adding the thinking distance and braking distance. Given:
Complete the sentence regarding thinking distance.
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Answer
The driver’s thinking distance is most likely to increase when A the driver is tired. This is because fatigue can slow reaction times, leading to a longer thinking distance before braking.
Step 3
Calculate the momentum of the car.
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Answer
Momentum is calculated using the formula:
extMomentum=extmassimesextvelocity
Given:
Mass = 800 kg
Velocity = 3.0 m/s
So:
extMomentum=800extkgimes3.0extm/s=2400extkgm/s
Thus, the momentum of the car is 2400 kg m/s.
Step 4
Calculate the work done by the braking force.
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Work done is calculated using the formula:
extWork=extForceimesextDistance
Given:
Force = 600 N
Distance = 15 m
So:
extWork=600extNimes15extm=9000extJ
Hence, the work done by the braking force is 9000 J.
Step 5
Complete the sentence regarding work done by the brakes.
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Answer
The work done by the brakes during braking is equal to A the energy transferred. This is because the work done on an object is equivalent to the energy transferred to stop it.
