Question

1. Першу половину свого шляху автомобіль рухається зі швидкістю 80 км/год, а другу половину шляху – зі швидкістю 40км/год. Яка середня швидкість руху автомобіля?

Answer 1

Calculation of Average Speed

To calculate the average speed of the car, we need to find the total distance traveled and the total time taken.

Let's assume that the total distance traveled by the car is D kilometers.

The car covers the first half of the distance, which is D/2 kilometers, at a speed of 80 km/h. The time taken to cover this distance can be calculated using the formula:

Time taken = Distance / Speed

For the first half of the distance, the time taken is:

Time taken for the first half = (D/2) / 80

Similarly, the car covers the second half of the distance, which is also D/2 kilometers, at a speed of 40 km/h. The time taken to cover this distance is:

Time taken for the second half = (D/2) / 40

To find the total time taken, we add the time taken for the first half and the time taken for the second half:

Total time taken = (D/2) / 80 + (D/2) / 40

Now, we can calculate the average speed using the formula:

Average speed = Total distance / Total time taken

Substituting the values, we get:

Average speed = D / [(D/2) / 80 + (D/2) / 40]

Simplifying the equation, we get:

Average speed = 2 * 80 * 40 / (80 + 40)

Calculating the average speed, we find:

Average speed = 53.33 km/h

Therefore, the average speed of the car is approximately 53.33 km/h.