Question

Расстояние между посёлками 250 км. Из этих посёлков одновременнов одном и томже направлении выехали грузовик и автобус. Грузовик проехал за час 45 км , а автобус 68 км. Какое расстояние было между машинами в начале движения? Какое расстояние стало между ними через час? увеличилоси или уменьшилось расстояние между машинами через час? какое расстояние будет между ними через 2 часа если... а)автобус позади грузовика , б)автобус впереди грузовика

Answer 1

В начале движения - 250 км
а) расстояние между ними уменьшается
   1)68-45=23(км)-на столько расстояние уменьшилось за час.
   2)250-23=227(км)-стало между ними через час.
   3)250-23-23=204(км)-стало между ними через 2 часа.
б) расстояние между ними увеличивается
   1)68-25=23(км)-на столько расстояние увеличилось за час.
   2)250+23=273(км)-стало между ними через час.
   3)250+23+23=296(км)-стало между ними через 2 часа.

Answer 2

Problem Analysis

We are given that the distance between two villages is 250 km. A truck and a bus start simultaneously from these villages in the same direction. The truck travels 45 km in one hour, and the bus travels 68 km in one hour. We need to determine the initial distance between the vehicles, the distance between them after one hour, whether the distance between them increased or decreased after one hour, and the distance between them after two hours if the bus is either behind or in front of the truck.

Solution

To solve this problem, we can use the following steps:

1. Calculate the initial distance between the truck and the bus. 2. Calculate the distance between the truck and the bus after one hour. 3. Determine whether the distance between them increased or decreased after one hour. 4. Calculate the distance between the truck and the bus after two hours, considering two scenarios: the bus is either behind or in front of the truck.

Let's calculate the values step by step.

Step 1: Initial Distance

The initial distance between the truck and the bus is equal to the total distance between the villages, which is 250 km.

Initial Distance = 250 km

Step 2: Distance after One Hour

To calculate the distance between the truck and the bus after one hour, we need to subtract the distance traveled by each vehicle from the initial distance.

Distance traveled by the truck = 45 km

Distance traveled by the bus = 68 km

Distance after one hour = Initial Distance - (Distance traveled by the truck + Distance traveled by the bus)

Distance after one hour = 250 km - (45 km + 68 km) = 250 km - 113 km = 137 km

Step 3: Change in Distance after One Hour

To determine whether the distance between the truck and the bus increased or decreased after one hour, we compare the distance after one hour with the initial distance.

If the distance after one hour is less than the initial distance, then the distance between the truck and the bus decreased.

If the distance after one hour is greater than the initial distance, then the distance between the truck and the bus increased.

In this case, the distance after one hour (137 km) is less than the initial distance (250 km), so the distance between the truck and the bus decreased after one hour.

The distance between the truck and the bus decreased after one hour.

Step 4: Distance after Two Hours

To calculate the distance between the truck and the bus after two hours, we need to consider two scenarios: the bus is either behind or in front of the truck.

a) If the bus is behind the truck: - Distance traveled by the truck after two hours = Distance traveled by the truck in one hour * 2 - Distance traveled by the bus after two hours = Distance traveled by the bus in one hour * 2 - Distance after two hours = Initial Distance - (Distance traveled by the truck after two hours + Distance traveled by the bus after two hours)

b) If the bus is in front of the truck: - Distance traveled by the truck after two hours = Distance traveled by the truck in one hour * 2 - Distance traveled by the bus after two hours = Distance traveled by the bus in one hour * 2 - Distance after two hours = Initial Distance + (Distance traveled by the truck after two hours - Distance traveled by the bus after two hours)

Let's calculate the distances after two hours for both scenarios.

a) If the bus is behind the truck: - Distance traveled by the truck after two hours = 45 km * 2 = 90 km - Distance traveled by the bus after two hours = 68 km * 2 = 136 km - Distance after two hours = 250 km - (90 km + 136 km) = 250 km - 226 km = 24 km

If the bus is behind the truck, the distance between them after two hours is 24 km.

b) If the bus is in front of the truck: - Distance traveled by the truck after two hours = 45 km * 2 = 90 km - Distance traveled by the bus after two hours = 68 km * 2 = 136 km - Distance after two hours = 250 km + (90 km - 136 km) = 250 km - 46 km = 204 km

If the bus is in front of the truck, the distance between them after two hours is 204 km.

To summarize:

- Initial Distance: 250 km - Distance after one hour: 137 km - Change in Distance after one hour: Decreased - Distance after two hours (bus behind truck): 24 km - Distance after two hours (bus in front of truck): 204 km

Please let me know if anything is unclear or if you need further assistance!