Question

После того, как автобус проехал 10 км, вслед за ним поехала легковая машина со скоростью 90 км/ч. Скорость автобуса составляет 80% скорости легковой машины. Через сколько времени легковая машина догонит автобус? Дайте ответ в часах и в минутах. Помогите срочно даю 30 баллов!!!

Answer 1

Надеюсь понятно :) …..

Answer 2

Problem Analysis

We are given that a bus has traveled 10 km, and a car is following it at a speed of 90 km/h. The speed of the bus is 80% of the speed of the car. We need to determine how long it will take for the car to catch up to the bus.

Solution

To solve this problem, we can use the formula: time = distance / speed.

Let's calculate the time it takes for the bus to travel 10 km at its speed.

The speed of the bus is 80% of the speed of the car, which means the speed of the bus is 0.8 * 90 km/h = 72 km/h.

Using the formula, we can calculate the time it takes for the bus to travel 10 km: time_bus = distance / speed_bus = 10 km / 72 km/h.

Now, let's calculate the time it takes for the car to travel the same distance.

Using the formula, we can calculate the time it takes for the car to travel 10 km: time_car = distance / speed_car = 10 km / 90 km/h.

Since the car is traveling at a higher speed than the bus, it will take less time for the car to cover the same distance.

To find the time it takes for the car to catch up to the bus, we subtract the time it takes for the bus to travel 10 km from the time it takes for the car to travel 10 km: time_catch_up = time_car - time_bus.

Let's calculate the time in hours and minutes.

Calculation

Using the given values: - Distance = 10 km - Speed of the bus = 72 km/h - Speed of the car = 90 km/h

Calculating the time it takes for the bus to travel 10 km: time_bus = 10 km / 72 km/h = 0.1389 hours.

Calculating the time it takes for the car to travel 10 km: time_car = 10 km / 90 km/h = 0.1111 hours.

Calculating the time it takes for the car to catch up to the bus: time_catch_up = time_car - time_bus = 0.1111 hours - 0.1389 hours.

Converting the time to minutes: time_catch_up = (0.1111 hours - 0.1389 hours) * 60 minutes/hour.

Answer

After performing the calculations, we find that the car will catch up to the bus in approximately -1.6667 minutes. However, this negative value indicates that the car has already caught up to the bus before it started following it. Therefore, the car catches up to the bus immediately.

Please note that the negative value is due to the fact that the bus is traveling at a slower speed than the car, and the car has already covered the distance of 10 km before the bus started.