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Sam drives his car on a journey - Edexcel - GCSE Maths - Question 3 - 2021 - Paper 2
Question 3
Sam drives his car on a journey. Here is the travel graph for the first 15 minutes of his journey. Distance travelled (kilometres) 0 10 20 30 40 50 ... show full transcript
Worked Solution & Example Answer:Sam drives his car on a journey - Edexcel - GCSE Maths - Question 3 - 2021 - Paper 2
Step 1
Work out Sam’s speed, in km/h, for the first 15 minutes of his journey.
Answer
To find Sam's speed, we need to calculate the distance he travelled during the first 15 minutes. From the graph, it can be determined that Sam travelled 25 km from 10:00 to 10:15.
Using the formula for speed:
[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} ]
Here, Distance = 25 km and Time = 15 minutes = \frac{15}{60} \text{ hours} = 0.25 \text{ hours}.
So,
[ \text{Speed} = \frac{25}{0.25} = 100 \text{ km/h} ]
Therefore, Sam’s speed for the first 15 minutes is 100 km/h.
Step 2
On the grid, complete the travel graph for Sam’s journey.
Answer
From 10:15 to 10:25, Sam stops for 10 minutes, so the graph remains horizontal from (10:15, 25) to (10:25, 25).
Then, he drives at a speed of 75 km/h for 20 minutes, which covers a distance of:
[ \text{Distance} = \text{Speed} \times \text{Time} = 75 \times \frac{20}{60} = 25 \text{ km} ]
Thus, from 10:25 to 10:45, the graph will rise from (10:25, 25) to (10:45, 50). The completed graph includes a horizontal line from (10:15, 25) to (10:25, 25) and a rising line from (10:25, 25) to (10:45, 50).