Question

Машина едит со скоростью 90 км/ч и прибыл к месту назначения за 5 ч 20 м. С какой скоростью должна ехать машина, что-бы проехать тоже расстояние на 48м раньше?Помогите!!! Решите на уровне 6 класса, но только пожалуйста, расспишите

Answer 1

1. Переведем время и скорость к общему измеритель - минуты. Скорость тогда будет 90км/60 минут и время в пути 5 ч 20 минут = 320 минут.
2. Если машина едет 90км за 60 минут, то за минуту она едет 90/60= 1,5 км, а за 320 минут она проедет 320*1,5= 480 км
3. Чтобы проехать 480 км на 48минут раньше, надо ехать 320-48=272 минуты.
4. 480/272=1,764706 км/минуту или 1,764706*60≈106 км/ч

Answer 2

Problem Analysis

We are given that a car travels at a speed of 90 km/h and arrives at its destination in 5 hours and 20 minutes. We need to find the speed at which the car should travel in order to cover the same distance 48 minutes earlier.

Solution

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

Let's denote the original speed of the car as v km/h and the original time taken as t hours. We are given that the original time taken is 5 hours and 20 minutes, which is equivalent to 5.33 hours.

We can set up the following equation based on the given information:

90 × 5.33 = v × t

To find the new speed at which the car should travel to arrive 48 minutes earlier, we need to find the new time taken. The new time taken will be t - 48 minutes, which is equivalent to t - 0.8 hours.

We can set up the following equation based on the new time taken:

v × (t - 0.8) = 90 × 5.33

Now we can solve these equations to find the value of v.

Calculation

Let's solve the equations:

Equation 1: 90 × 5.33 = v × t

Equation 2: v × (t - 0.8) = 90 × 5.33

Substituting the value of t from Equation 1 into Equation 2:

v × (5.33 - 0.8) = 90 × 5.33

Simplifying:

v × 4.53 = 90 × 5.33

Dividing both sides by 4.53:

v = (90 × 5.33) / 4.53

Calculating:

v ≈ 105.7 km/h

Therefore, the car should travel at a speed of approximately 105.7 km/h in order to arrive at the destination 48 minutes earlier.

Answer

The car should travel at a speed of approximately 105.7 km/h in order to cover the same distance 48 minutes earlier.

Please note that this solution is based on the information provided and assumes constant speed throughout the journey.