The distance-time graph shows information about part of a car journey - Edexcel - GCSE Maths - Question 16 - 2018 - Paper 2
Question 16
The distance-time graph shows information about part of a car journey.
Use the graph to estimate the speed of the car at time 5 seconds.
(Total for Question 14 is ... show full transcript
Worked Solution & Example Answer:The distance-time graph shows information about part of a car journey - Edexcel - GCSE Maths - Question 16 - 2018 - Paper 2
Step 1
Draw a tangent to the curve at time = 5 seconds
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Answer
Locate the point on the graph at time = 5 seconds, which corresponds to a distance of approximately 130 meters. Draw a straight line (tangent) that touches the curve at this point without crossing it.
Step 2
Find the gradient of the tangent
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Answer
To calculate the speed (gradient), select two points on the tangent line, for example, (3, 90) and (7, 160). Calculate the gradient using the formula:
ext{Gradient} = rac{ ext{change in distance}}{ ext{change in time}} = rac{160 - 90}{7 - 3} = rac{70}{4} = 17.5 ext{ m/s}
This indicates the speed of the car at that moment.
Step 3
State the estimated speed
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Answer
The estimated speed of the car at 5 seconds is therefore approximately 17.5 m/s.
