Question

Из двух городов,расстояние между которыми 90км.ч. одновременно в одно направление выехали автомобилист и мотоциклис со скоростью 75км.ч.,а скорость мотоциклиста состовляет две пятых скорости автомобилиста.Через сколько времениони встретятся?Какое расстаяние будет между ними через 1 час после начала движения?

Answer 1

1)  75 км/ч* 2/5 = 30 км/ч -  скорость мотоциклиста.
2) 75 - 30 = 45 км/ч - скорость сближения (догоняет автомобиль)
3) 90 км  :45 км/ч = 2 ч -  время встречи - ОТВЕТ
4)  45 км/ч * 1 ч = 45 км -  расстояние через 1 час - ОТВЕТ

Answer 2

Problem Analysis

We have two vehicles, a car and a motorcycle, traveling in the same direction between two cities that are 90 km apart. The car is traveling at a speed of 75 km/h, while the motorcycle's speed is two-fifths (2/5) of the car's speed. We need to determine the time it takes for them to meet and the distance between them after 1 hour of travel.

Time to Meet

To find the time it takes for the car and motorcycle to meet, we can use the formula:

Time = Distance / Relative Speed

The relative speed is the difference in their speeds since they are traveling in the same direction. Let's calculate the relative speed:

Relative Speed = Car Speed - Motorcycle Speed

Now we can substitute the values into the formula:

Time = Distance / Relative Speed

Distance between them after 1 hour

To find the distance between the car and motorcycle after 1 hour of travel, we can use the formula:

Distance = Relative Speed * Time

We already have the relative speed from the previous calculation, and the time is 1 hour.

Calculation

Let's calculate the time it takes for the car and motorcycle to meet and the distance between them after 1 hour of travel.

Solution

1. Calculate the relative speed: - Car Speed: 75 km/h - Motorcycle Speed: (2/5) * 75 km/h = 30 km/h - Relative Speed = Car Speed - Motorcycle Speed = 75 km/h - 30 km/h = 45 km/h

2. Calculate the time it takes for them to meet: - Distance: 90 km - Time = Distance / Relative Speed = 90 km / 45 km/h = 2 hours

3. Calculate the distance between them after 1 hour of travel: - Relative Speed: 45 km/h - Time: 1 hour - Distance = Relative Speed * Time = 45 km/h * 1 hour = 45 km

Therefore, it will take 2 hours for the car and motorcycle to meet, and after 1 hour of travel, the distance between them will be 45 km.