Question

Из двух поселков, расстояние между которыми 320км одновременно в одном направлении выехали 2 автомобиля. Скорость первого 85км/ч, а второго 65км/ч. Через сколько часов второй автомобиль догонит первый?

Answer 1

1)85-65=20(км/ч) скорость сближения
2)320:20=16 (ч)

Answer 2

Problem Analysis

We have two cars traveling in the same direction from two different towns. The distance between the towns is 320 km. The first car is traveling at a speed of 85 km/h, and the second car is traveling at a speed of 65 km/h. We need to determine how many hours it will take for the second car to catch up to the first car.

Solution

To solve this problem, we can use the formula:

Time = Distance / Speed

Let's calculate the time it will take for the second car to catch up to the first car.

Calculation

The distance between the two towns is 320 km. The first car is traveling at a speed of 85 km/h, and the second car is traveling at a speed of 65 km/h.

Let's assume that the second car catches up to the first car after t hours.

The distance traveled by the first car in t hours is given by:

Distance traveled by the first car = Speed of the first car * Time

The distance traveled by the second car in t hours is given by:

Distance traveled by the second car = Speed of the second car * Time

Since the second car catches up to the first car, the distances traveled by both cars must be equal. Therefore, we can set up the following equation:

Distance traveled by the first car = Distance traveled by the second car

Speed of the first car * Time = Speed of the second car * Time

Simplifying the equation, we get:

85t = 65t

Dividing both sides of the equation by t, we get:

85 = 65

Since the equation is true, it means that the second car catches up to the first car after t hours.

Therefore, the second car will catch up to the first car in t = 0 hours.

Answer

The second car will catch up to the first car immediately, as they are already traveling at the same speed.