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A car travels for 18 minutes at an average speed of 72 km/h - Edexcel - GCSE Maths - Question 9 - 2019 - Paper 1
Question 9
A car travels for 18 minutes at an average speed of 72 km/h. (a) How far will the car travel in these 18 minutes? David says. "72 kilometres per hour is faster th... show full transcript
Worked Solution & Example Answer:A car travels for 18 minutes at an average speed of 72 km/h - Edexcel - GCSE Maths - Question 9 - 2019 - Paper 1
Step 1
How far will the car travel in these 18 minutes?
Answer
To find the distance traveled by the car, we can use the formula:
Given that the speed is 72 km/h, we need to convert the time from minutes to hours:
ext{Time in hours} = rac{18}{60} = 0.3 ext{ hours}Now we can calculate the distance:
Thus, the car will travel 21.6 km in 18 minutes.
Step 2
Is David correct?
Answer
To determine if David is correct, we need to compare the speeds: 72 km/h and 20 m/s.
First, convert 72 km/h to m/s:
72 ext{ km/h} = rac{72 imes 1000}{3600} = 20 ext{ m/s}Now, we can see that:
- 72 km/h is equal to 20 m/s.
Since 72 km/h is not faster than 20 m/s, David's statement is incorrect.