Question

Расстояние между двумя пристанями равно 123,2 км. Из них одновременно навстречу друг другу вышли две лодки, скорости которых в стоячей воде равны. Через 2,8 ч. лодки встретились. Скорость течения реки равна 3 км/ч. Скорость лодки в стоячей воде равна км/ч. Сколько километров до места встречи пройдёт лодка, плывущая по течению? км. Сколько километров до места встречи пройдёт лодка, плывущая против течения? км.

Answer 1

собственная скорость это и есть скорость в стоячей воде

Answer 2

#### Problem Analysis We are given that the distance between two piers is 123.2 km. Two boats start simultaneously from each pier and meet after 2.8 hours. The speed of the river current is 3 km/h, and the speed of the boats in still water is unknown. We need to find the distance traveled by the boat moving with the current and against the current. #### Solution Let's assume the speed of the boats in still water is **x** km/h. To find the distance traveled by the boat moving with the current, we can use the formula: **distance = speed × time**. The boat moving with the current will have a combined speed of **(x + 3)** km/h. The time taken is 2.8 hours. Therefore, the distance traveled by the boat moving with the current is **(x + 3) × 2.8** km. To find the distance traveled by the boat moving against the current, we can use the same formula. The boat moving against the current will have a combined speed of **(x - 3)** km/h. The time taken is 2.8 hours. Therefore, the distance traveled by the boat moving against the current is **(x - 3) × 2.8** km. Let's calculate the distances. #### Calculation The distance traveled by the boat moving with the current is **(x + 3) × 2.8** km. The distance traveled by the boat moving against the current is **(x - 3) × 2.8** km. #### Substituting Values Substituting the given values, we have: - Distance between the piers = 123.2 km - Time taken = 2.8 hours - Speed of the river current = 3 km/h We need to find: - Distance traveled by the boat moving with the current - Distance traveled by the boat moving against the current #### Calculation The distance traveled by the boat moving with the current is **(x + 3) × 2.8** km. The distance traveled by the boat moving against the current is **(x - 3) × 2.8** km. #### Answer The distance traveled by the boat moving with the current is **(x + 3) × 2.8** km. The distance traveled by the boat moving against the current is **(x - 3) × 2.8** km. Please provide the value of **x** (the speed of the boats in still water) to calculate the distances.