Question

Электромобиль должен проехать расстояние между двумя городами, равное 420 км за 7 часов. Первые 2 часа ое ехал со скоростью на 5 км/ч меньше, чем должен был. С какой скоростью он должен проехать оставшийся путь,чтобы приехать без опоздания?

Answer 1

Ответ:

Со скоростью 82 км/ч

Пошаговое объяснение:

1) 7-2=5 (ч) осталось

2) 2×5=10 (км) за 2 часа

3) 420-10=410 (км) ему ещё надо проехать

4) 410:5=82 (км/ч)

Answer 2

To find the speed at which the electric car should travel for the remaining distance in order to arrive on time, we can break down the problem into two parts: the first two hours and the remaining time.

Calculating the speed for the first two hours:

Let's assume the car's normal speed is x km/h. According to the problem, for the first two hours, the car traveled at a speed that was 5 km/h slower than it should have been. Therefore, the speed for the first two hours can be calculated as (x - 5) km/h.

Calculating the remaining speed:

To calculate the remaining speed, we need to determine the distance traveled during the first two hours and subtract it from the total distance of 420 km. The remaining distance can be calculated as (420 km - 2 hours * (x - 5) km/h).

Now, we can calculate the speed for the remaining distance by dividing the remaining distance by the remaining time, which is 7 hours minus the first two hours:

Remaining speed = (Remaining distance) / (Remaining time)

Substituting the values, we get:

Remaining speed = (420 km - 2 hours * (x - 5) km/h) / (7 hours - 2 hours)

Simplifying the equation, we have:

Remaining speed = (420 km - 2x + 10 km/h) / 5 hours

To find the value of x, we can solve the equation:

(420 km - 2x + 10 km/h) / 5 hours = x km/h

Let's solve this equation to find the value of x.