Question

Катер прошел против течения реки 21,6 км за 1,2 ч,а по течению реки за то же время-расстояние на 4,8 км большее.Чему равна собственная скорость катера и скорость течения реки?

Answer 1

21,6км=21600м
4,8км=4800м
1,2ч=80 мин
21600:80=270(м/ч )-V катера против течения реки
21600+480=26400(м)-S катера по течению реки
26400:80=330(м/ч ) V катера по течению реки
330-270=60(м/ч)
Ответ:60 м/ч скорость течения реки.
V- скорость
S- расстояние

Answer 2

Calculation of the Boat's Speed and River Current Speed

To find the boat's speed and the speed of the river current, we can use the given information about the boat's travel time and distances.

Let's denote the boat's speed as x km/h and the speed of the river current as y km/h.

According to the problem statement, the boat traveled 21.6 km against the river current in 1.2 hours. This means that the effective speed of the boat against the current is the difference between the boat's speed and the current's speed: (x - y) km/h.

Similarly, when the boat travels with the river current, the effective speed of the boat is the sum of the boat's speed and the current's speed: (x + y) km/h.

We are also given that the distance traveled with the river current is 4.8 km more than the distance traveled against the current.

Using the formula distance = speed × time, we can set up the following equations:

1. When traveling against the current: - Distance = 21.6 km - Time = 1.2 hours - 21.6 = (x - y) × 1.2 2. When traveling with the current: - Distance = 21.6 km + 4.8 km = 26.4 km - Time = 1.2 hours - 26.4 = (x + y) × 1.2 Now, let's solve these equations to find the values of x (boat's speed) and y (river current's speed).

Solving the Equations

We can start by rearranging the equations to solve for x and y:

1. Equation 1: 21.6 = (x - y) × 1.2 - Simplifying, we get: 25.92 = x - y

2. Equation 2: 26.4 = (x + y) × 1.2 - Simplifying, we get: 21.92 = x + y

Now, we can solve this system of equations to find the values of x and y.

Adding the two equations together, we get: 25.92 + 21.92 = x - y + x + y Simplifying, we have: 47.84 = 2x Dividing both sides by 2, we find: x = 23.92

Substituting the value of x back into either of the original equations, we can solve for y.

Using Equation 1: 25.92 = x - y Substituting x = 23.92, we have: 25.92 = 23.92 - y Simplifying, we find: y = 23.92 - 25.92 y = -2

Answer

The boat's speed is 23.92 km/h and the speed of the river current is -2 km/h.

Please note that the negative sign for the river current speed indicates that the current is flowing in the opposite direction of the boat's travel.