Question

Из двух городов расстояние между которыми равно 140 км, одновременно в противоположных направлениях выехали два автомобиля. Скорость движения одного автомобиля 80 км/ч. Найди скорость движения второго автомобиля если через 4 часа расстояние между ними составляет 820 км

Answer 1

820/4=205 километров в час 

Answer 2

80км/ч×4ч=320 км (проехал первый)
320+140=460 км (расстояние за 4 часа от первого до пункта отправления второго) 
820-460=360 км (проехал второй) 
360км÷4ч= 90 км/ч
Ответ: скорость второго 90км/ч

Answer 3

Problem Analysis

We are given that the distance between two cities is 140 km. Two cars start simultaneously from these cities in opposite directions. The speed of one car is 80 km/h. We need to find the speed of the second car if after 4 hours the distance between them is 820 km.

Solution

Let's assume the speed of the second car is x km/h.

After 4 hours, the first car would have traveled a distance of 80 * 4 = 320 km. The second car, traveling in the opposite direction, would have traveled a distance of x * 4 km.

The total distance between the two cars after 4 hours is given as 820 km. Therefore, we can write the equation:

320 + x * 4 = 820

Simplifying the equation, we get:

x * 4 = 820 - 320

x * 4 = 500

Dividing both sides of the equation by 4, we find:

x = 500 / 4

x = 125

Therefore, the speed of the second car is 125 km/h.

Answer

The speed of the second car is 125 km/h.