Question

Скорый поезд, двигаясь со средней скоростью 80км/ч,проходит расстояние между двумя городами за 12 ч. За какое время пройдет это расстояние автомобиль, если его средняя скорость на 20 км/ч меньше средней скорости скорого поезда?

Answer 1

1) 80*12=960 км расстояние между двумя городами

2) 80-20 = 60 км/ч - средняя скорость автомобиля

3) 960: 60 = 16 часов проходит автомобиль

Answer 2

Вычислим скорость автомобиля
80-20=60 (км/ч)

Вычислим расстояние между городами
S=V*t
S=80*12=960 (км)

Вычислим время автомобиля
t=S:V
t=960:60=16 (ч)

Ответ: за 16 часов проедет автомобиль между городами.

Answer 3

Calculation of Time for the Car to Cover the Distance

To calculate the time it will take for the car to cover the same distance, we need to know the average speed of the car and the distance between the two cities.

Given: - The fast train travels at an average speed of 80 km/h. - The fast train takes 12 hours to cover the distance between the two cities.

We need to find: - The time it will take for the car to cover the same distance, given that its average speed is 20 km/h less than the average speed of the fast train.

Let's assume the distance between the two cities is D km.

To find the time it will take for the car to cover the distance, we can use the formula:

Time = Distance / Speed

The speed of the car is 20 km/h less than the speed of the fast train, so the speed of the car is (80 km/h - 20 km/h) = 60 km/h.

Substituting the values into the formula, we get:

Time = D km / 60 km/h

Since the fast train takes 12 hours to cover the distance, we can set up the equation:

12 = D km / 60 km/h

To solve for D, we can multiply both sides of the equation by 60 km/h:

12 * 60 km/h = D km

Simplifying the equation, we get:

720 km = D

Therefore, the distance between the two cities is 720 km.

Now, we can substitute the value of D into the formula for time:

Time = 720 km / 60 km/h

Simplifying the equation, we get:

Time = 12 hours

So, it will take the car 12 hours to cover the distance between the two cities, assuming its average speed is 20 km/h less than the average speed of the fast train.

Please note that the calculations are based on the given information and assumptions made.