Question

Два самолета вылетают одновременно из пунктов А и В и летят навстречу друг другу с постоянными скоростями. Их встреча произошла через три часа после вылета, и еще через два часа первый самолет приземлился в В. Через какое время после вылета приземлится в А второй самолет?

Answer 1

Через 50минут! вроде так!

Answer 2

Problem Analysis

Two planes, flying from points A and B towards each other at constant speeds, meet after three hours. After two more hours, the first plane lands at point B. We need to find out how long after takeoff the second plane will land at point A.

Solution

Let's denote the speed of the first plane as v and the speed of the second plane as u. We know that the time it takes for the two planes to meet is 3 hours, and the first plane lands at point B after 5 hours.

Using the formula distance = speed × time, we can set up the following equations: 1. For the first plane: 3v = d (where d is the distance between A and B) 2. For the second plane: 5u = d

We also know that the total distance between A and B is covered by both planes, so d = (3v + 5u).

By substituting the value of d from the second equation into the third equation, we get: 3v + 5u = 8u.

Solving for u, we find: u = (3v)/3 = v.

This means that the speeds of the two planes are equal. Therefore, the time it takes for the second plane to land at point A will be the same as the time it took for the first plane to land at point B, which is 5 hours.

Answer: The second plane will land at point A 5 hours after takeoff.