To solve this question, we can use the formula for average speed:
Average Speed = Total Distance / Total Time
Let's assume the driver took t1 hours to complete the first 2 km at a speed of 120 km/h. Therefore, the time taken for the first 2 km is t1 hours.
Given that the driver has to average 240 km/h for the entire 4 km race course, we can calculate the total time taken to complete the race course using the formula:
Total Time = Total Distance / Average Speed
Total Time = 4 km / 240 km/h = 1/60 hours
Now, let's find the time taken to complete the second 2 km of the race course.
Time taken for the second 2 km = Total Time - Time taken for the first 2 km
Time taken for the second 2 km = (1/60) - t1
Now, we can calculate the speed needed to average 240 km/h for the entire course:
Speed for the second 2 km = Distance / Time taken for the second 2 km
Speed for the second 2 km = 2 km / ((1/60) - t1)
To average 240 km/h for the entire course, the speed for the second 2 km must be:
240 km/h = 2 km / ((1/60) - t1)
Simplifying this equation:
240 km/h = 2 km / ((1/60) - t1)
240 km/h = 2 km / (60 - 60t1)
240 km/h = 2 km / (60 - 60t1)
240 km/h = 1 / (30 - 30t1)
30 - 30t1 = 1/240
-30t1 = 1/240 - 30
t1 = (1/240 - 30) / -30
By calculating the value of t1, we can determine the speed for the second 2 km. However, this calculation results in a negative value for t1, which is not possible. Therefore, there is no valid speed for the second 2 km that would allow the driver to average 240 km/h for the entire course.
Hence, the correct answer is E) none of the above.