Question

Турист переплыл море на катере со средней скоростью 50 км/ч. Обратно он летел на самолёте со скоростью 450 км/ч. Найдите среднюю скорость туриста на протяжении всего пути.

Answer 1

Чтобы найти сред­нюю ско­рость на про­тя­же­нии пути, нужно весь путь раз­де­лить на все время дви­же­ния. Пусть 2x км — весь путь пу­те­ше­ствен­ни­ка, тогда сред­няя ско­рость равна: 2x:(x/50 + x/450) приводим к общему знаменателю = 2x: 9x+x/450 = 2x*450/10x = 90 км/ч

Answer 2

Calculation of Average Speed

To find the average speed of the tourist throughout the entire journey, we need to calculate the total distance traveled and the total time taken.

Let's assume that the distance traveled in one direction is D.

The time taken to travel by boat at a speed of 50 km/h is given by:

Time taken by boat = Distance / Speed = D / 50

The time taken to travel by plane at a speed of 450 km/h is given by:

Time taken by plane = Distance / Speed = D / 450

The total time taken for the entire journey is the sum of the time taken by boat and the time taken by plane:

Total time = Time taken by boat + Time taken by plane = D / 50 + D / 450

The total distance traveled is twice the distance traveled in one direction:

Total distance = 2D

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

Average speed = Total distance / Total time = (2D) / (D / 50 + D / 450)

Simplifying the equation:

Average speed = (2D) / (D(1/50 + 1/450))

Now, let's calculate the average speed.