Average, minimum and maximum speed of the kayak.
Kayaks are rowing boats with a pointed bow and stern, which are widely used today in tourism, water sports, hunting, family outings and long trips through reservoirs of varying complexity. They are maneuverable, light and obedient in control, have a low weight, excellent stability and buoyancy. Therefore, in recent years, many lovers of pastime on the water, who are very interested in the running and technical characteristics of various models, are striving to purchase a kayak of one type or another. Not the last place in them is the speed of kayaks.
I must say that the speed of such boats is a loose concept, depending on many factors. It is influenced by the features of the current, and the physical qualities of the rowers, and the dimensions of the boat, and the type of water, and much more. Theoretically, it ranges from 4 kilometers per hour to 5 kilometers per hour, but in practice, the figures can vary significantly. In fact, the approximate speed of a particular kayak model is important for planning routes, and beginners usually focus on tests of single, double, triple kayaks of various designs. But these are just conditional data that were obtained by passing the same short distances by different kayaks. And on long journeys, they can change a lot.
Average kayak speed
Kayaks are rowing boats, which means that their speed is highly dependent on the physical strength and experience of the rowers. Models with a length of 3.5 meters are capable of accelerating to 7 kilometers per hour or more, even if their passengers do not make any special efforts and row calmly. At the same time, if the rowers are inexperienced, do not know how to keep the course, the boats begin to yaw, and their speed can drop to 3-4 kilometers per hour. Beginners in such cases try to gain it by speeding up from time to time, but this often only deprives them of their strength and leads to rapid fatigue.
In general, experienced kayakers, going on long trips, try to keep an average speed of about 6-7 kilometers per hour. This gives them the opportunity to row for 7-8 hours and at the same time feel quite cheerful. Of course, by the end of the movement, the speed of the kayak will still fall, but the route will be completed.
It is believed that the average speed of kayaks with two or three paddlers is higher than that of single-seat models. It is true for sports models, but does not always apply to. If the boat goes on a trip with a crew of two or three people, it usually also carries luggage. Under the weight of such a load, the kayak will give a decent draft, the water resistance will increase, therefore, the speed will remain the same. And if the rowers still do not know how to work in a team or are very different in physical qualities, it will decrease due to inconsistency in strokes and lack of coordination in actions.
Kayak speed in still water
In practice, the speed of a kayak is highly dependent on both the current and the direction of the wind. If the water is still and the weather is calm, one rower can easily accelerate the boat to 7 kilometers per hour, and some models even pick up speed up to 12 kilometers per hour. We are not talking now about inflatable options without frames, for which 6 kilometers per hour is the limit due to constant yaw. Recently, manufacturers have begun to produce kayaks with hydrofoils or a motor that can move at speeds up to 40 kilometers per hour!
Quiet view and lack of wind are just ideal conditions that can not always be found. In addition, they often change quickly, so you always need to be careful with speed and focus on the weather and the presence of currents on the route.
The speed of the kayak downstream
The speed of a kayak moving along water bodies with a current of various kinds depends on its speed and direction. If the boat is going with the flow, its speed often does not matter, and the rowers in this case only have to maneuver. For example, the speed of a river is about 20 kilometers per hour. This means that there is no need to add another 5 kilometers of the kayak's own speed to this value. It is only important to carry out maneuvers correctly so as not to run into obstacles and shallows. In this case, you should not count on the fact that the boat will move at the speed of the current. It is all sorts of obstacles, rocky shoals that require maneuvering, can significantly interfere with this.
If a kayak is going against a current that is moving faster than 2 kilometers per hour, it may not move forward at all. In general, tourists try to avoid such reservoirs, but sometimes such areas come across on the routes. Then the crew disembarks from the boat, leaving equipment and cargo in it, and guides the kayak on a rope or line. The boat in this case moves at a speed of about 5 kilometers per hour, provided that the shore is sandy or just hard and even.
The maximum speed of the sport kayak
Sports kayaks are usually monolithic models with a streamlined shape and can accommodate from one to three paddlers. They are designed for competition, so they are high-speed lightweight options. On average, such boats develop speeds from 9 kilometers per hour to 12 kilometers per hour, but the maximum records in rowing slalom ranged from 17 to 18 kilometers per hour. Of course, they were achieved by professional athletes with extensive training experience. However, ordinary owners of sports kayaks on short distances can accelerate to 15 kilometers per hour if the boat moves on suitable water. It is important in this case to take into account the features of the model, the current, not to try to load it more than the load capacity indicated in the characteristics and not to overestimate your own skills and capabilities.
This material is a system of tasks on the topic “Movement”.
Purpose: to help students more fully master the technologies for solving problems on this topic.
Tasks for movement on water.
Very often a person has to make movements on water: river, lake, sea.
At first he did it himself, then rafts, boats, sailing ships appeared. With the development of technology, steamships, motor ships, nuclear-powered ships came to the aid of man. And he was always interested in the length of the path and the time spent on overcoming it.
Imagine that it is spring outside. The sun melted the snow. Puddles appeared and streams ran. Let's make two paper boats and put one of them into a puddle, and the second into a stream. What will happen to each of the ships?
In a puddle, the boat will stand still, and in a stream it will float, as the water in it "runs" to a lower place and carries it with it. The same will happen with a raft or a boat.
In the lake they will stand still, and in the river they will swim.
Consider the first option: a puddle and a lake. Water does not move in them and is called standing.
The boat will float through the puddle only if we push it or if the wind blows. And the boat will begin to move in the lake with the help of oars or if it is equipped with a motor, that is, due to its speed. Such a movement is called movement in still water.
Is it different from driving on the road? Answer: no. And this means that we know how to act in this case.
Problem 1. The speed of the boat on the lake is 16 km/h.
How far will the boat travel in 3 hours?
Answer: 48 km.
It should be remembered that the speed of a boat in still water is called own speed.
Problem 2. A motorboat sailed 60 km across the lake in 4 hours.
Find the own speed of the motorboat.
Answer: 15 km/h.
Task 3. How long will it take for a boat whose own speed is
equals 28 km/h to swim 84 km across the lake?
Answer: 3 hours.
So, To find the distance traveled, you need to multiply the speed by the time.
To find the speed, you need to divide the distance by the time.
To find the time, you need to divide the distance by the speed.
What is the difference between driving on a lake and driving on a river?
Recall a paper boat in a stream. It floated because the water in it moves.
Such a movement is called downstream. And in the opposite direction - moving against the current.
So, the water in the river moves, which means it has its own speed. And they call her river speed. (How to measure it?)
Problem 4. The speed of the river is 2 km/h. How many kilometers does the river
any object (wood chip, raft, boat) in 1 hour, in 4 hours?
Answer: 2 km/h, 8 km/h.
Each of you swam in the river and remembers that it is much easier to swim with the current than against the current. Why? Because in one direction the river "helps" to swim, and in the other it "hinders".
Those who do not know how to swim can imagine a situation where a strong wind is blowing. Consider two cases:
1) the wind blows in the back,
2) the wind blows in the face.
In both cases it is difficult to go. The wind in the back makes us run, which means that the speed of our movement increases. The wind in the face knocks us down, slows down. The speed is thus reduced.
Let's take a look at the flow of the river. We have already talked about the paper boat in the spring stream. The water will carry it along with it. And the boat, launched into the water, will float with the speed of the current. But if she has her own speed, then she will swim even faster.
Therefore, in order to find the speed of movement along the river, it is necessary to add the own speed of the boat and the speed of the current.
Problem 5. The own speed of the boat is 21 km/h, and the speed of the river is 4 km/h. Find the speed of the boat along the river.
Answer: 25km/h.
Now imagine that the boat has to sail against the current of the river. Without a motor, or at least an oar, the current would carry her in the opposite direction. But, if you give the boat its own speed (start the engine or land a rower), the current will continue to push it back and prevent it from moving forward at its own speed.
So to find the speed of the boat against the current, it is necessary to subtract the speed of the current from its own speed.
Problem 6. The speed of the river is 3 km/h, and the own speed of the boat is 17 km/h.
Find the speed of the boat against the current.
Answer: 14 km/h.
Problem 7. The own speed of the ship is 47.2 km/h, and the speed of the river is 4.7 km/h. Find the speed of the boat upstream and downstream.
Answer: 51.9 km / h; 42.5 km/h.
Problem 8. The speed of a motor boat downstream is 12.4 km/h. Find the own speed of the boat if the speed of the river is 2.8 km/h.
Answer: 9.6 km/h.
Problem 9. The speed of the boat against the current is 10.6 km/h. Find the boat's own speed and the speed with the current if the speed of the river is 2.7 km/h.
Answer: 13.3 km/h; 16 km/h
Relationship between downstream and upstream speed.
Let us introduce the following notation:
V s. - own speed,
V tech. - flow speed,
V on current - flow speed,
V pr.tech. - speed against the current.
Then the following formulas can be written:
V no tech = V c + V tech;
V n.p. flow = V c - V flow;
Let's try to represent it graphically:
Conclusion: the difference in velocities downstream and upstream is equal to twice the current velocity.
Vno tech - Vnp. tech = 2 Vtech.
Vtech \u003d (V by tech - Vnp. tech): 2
1) The speed of the boat upstream is 23 km/h and the speed of the current is 4 km/h.
Find the speed of the boat with the current.
Answer: 31 km/h.
2) The speed of a motorboat downstream is 14 km/h/ and the speed of the current is 3 km/h. Find the speed of the boat against the current
Answer: 8 km/h.
Task 10. Determine the speeds and fill in the table:
* - when solving item 6, see Fig.2.
Answer: 1) 15 and 9; 2) 2 and 21; 3) 4 and 28; 4) 13 and 9; 5) 23 and 28; 6) 38 and 4.
