Question

За 5,5 ч против течения реки катер проходит тот же путь,что за 4,5 ч по течению. Найдите собственную скорость катера,если скорость течения реки 2 км/ч.

Answer 1

V-?
5,5(x-2)=4,5(x+2)
5,5x-11=4,5x+9
5,5x-4,5x=9+11
x=20( км/ч)

Answer 2

Пусть х- собственная скорость катера, тогда v по течению = х+2.4 км\ч

v против течения х-2.4 км\ч. При этом, так как S одинаковое получаем уравнение 5х+2.4*5=6.25*2.4

5ч+12=6.25х-15, отсюда

х=21.6 км\ч

(6.25 это переведённые 6ч.15мин в часы)

Answer 3

Finding the Speed of the Boat

To find the speed of the boat, we can use the formula: Speed = Distance / Time

Given: - Time taken against the current = 5.5 hours - Time taken with the current = 4.5 hours - Speed of the current = 2 km/h

Let's denote the speed of the boat as B.

Calculating the Boat's Speed

When traveling against the current, the effective speed of the boat is (B - 2) km/h, and when traveling with the current, the effective speed of the boat is (B + 2) km/h.

Using the formula Speed = Distance / Time, we can set up the following equations based on the given times and speeds:

1. Distance = (B - 2) * 5.5 (against the current) 2. Distance = (B + 2) * 4.5 (with the current)

Equating the distances traveled in both cases, we can solve for the speed of the boat.

Solving for the Boat's Speed

Let's solve the equations to find the speed of the boat:

1. (B - 2) * 5.5 = (B + 2) * 4.5

Expanding and solving for B: - 5.5B - 11 = 4.5B + 9 - 5.5B - 4.5B = 9 + 11 - B = 20 km/h

Conclusion

Therefore, the speed of the boat (in still water) is 20 km/h.