Question

Из города одновременно в одном направлении выехали грузовая машина со скоростью 90 км/ч и легковой автомобиль , скорость которого 115 км/ч . На сколько километров грузовик отстанет от автомобиля через 3 ч после начала движения? Постарайтесь найти два способа решения этой задачи.

Answer 1

1)способ  90*3=270 (км) 
               115*3=345 (км)
                345-270=75 (км)   Ответ на 75 км

2)способ   (115-90)*3 =75 (км) Ответ на 75 км

Answer 2

Problem Statement

В городе одновременно в одном направлении выехали грузовая машина со скоростью 90 км/ч и легковой автомобиль, скорость которого 115 км/ч. На сколько километров грузовик отстанет от автомобиля через 3 ч после начала движения? Постарайтесь найти два способа решения этой задачи.

Solution 1: Using Relative Speed

To find the distance by which the truck falls behind the car after 3 hours, we can use the concept of relative speed. The relative speed is the difference between the speeds of the two vehicles.

The relative speed of the truck with respect to the car is calculated by subtracting the speed of the car from the speed of the truck:

Relative speed = Speed of truck - Speed of car

Substituting the given values:

Relative speed = 90 km/h - 115 km/h = -25 km/h

Since the relative speed is negative, it means that the truck is falling behind the car.

To find the distance, we can use the formula:

Distance = Relative speed * Time

Substituting the values:

Distance = -25 km/h * 3 h = -75 km

Therefore, the truck falls behind the car by 75 kilometers after 3 hours.

Solution 2: Using Distance = Speed * Time

Another way to solve this problem is by using the formula Distance = Speed * Time.

The distance traveled by the truck after 3 hours is calculated by multiplying the speed of the truck by the time:

Distance truck = Speed truck * Time

Substituting the given values:

Distance truck = 90 km/h * 3 h = 270 km

Similarly, the distance traveled by the car after 3 hours is calculated by multiplying the speed of the car by the time:

Distance car = Speed car * Time

Substituting the given values:

Distance car = 115 km/h * 3 h = 345 km

The difference between the distances traveled by the truck and the car gives us the distance by which the truck falls behind the car:

Distance = Distance car - Distance truck

Substituting the values:

Distance = 345 km - 270 km = 75 km

Therefore, the truck falls behind the car by 75 kilometers after 3 hours.

Both methods yield the same result, which is that the truck falls behind the car by 75 kilometers after 3 hours.

Please let me know if you need any further clarification.