The graph shows the speed of a car, in metres per second, during the first 20 seconds of a journey - Edexcel - GCSE Maths - Question 15 - 2018 - Paper 3

To estimate the distance travelled, we can approximate the area under the graph using 4 equal-width strips. Since the graph represents speed vs. time, the area will provide the distance.

1. Determine the width of each strip: Since the total time is 20 seconds and we are using 4 strips, the width of each strip is:

   [ \text{Width} = \frac{20 \text{ s}}{4} = 5 \text{ s} ]

2. Identify the speeds at each interval: We divide the time into four intervals of 5 seconds:

   • From 0 to 5 seconds: approximately 10 m/s
   • From 5 to 10 seconds: approximately 20 m/s
   • From 10 to 15 seconds: approximately 30 m/s
   • From 15 to 20 seconds: approximately 35 m/s

3. Calculate the area of each strip:

   • Strip 1: Area = Speed * Time = 10 m/s * 5 s = 50 m
   • Strip 2: Area = 20 m/s * 5 s = 100 m
   • Strip 3: Area = 30 m/s * 5 s = 150 m
   • Strip 4: Area = 35 m/s * 5 s = 175 m

4. Sum the areas:

   [ \text{Total Distance} = 50 + 100 + 150 + 175 = 475 \text{ m} ]

Thus, an estimate for the distance the car travelled in the first 20 seconds is approximately 475 m.