Sources: Museum of New Zealand Te Papa Tongarewa, Registration no. ME012263. Maui Solomon, Museum of New Zealand Te Papa Tongarewa. Registration no. ME016510. Hektor Busby, Auckland Art Gallery Toi o Tamaki. John Kinder collection, Alexander Turnbull Library, Wellington, New Zealand. Photograph taken by Ian Mackley. Reference no. EP/1974/0309/3A-F

Investigations into the pūtaiao (Physics - Forces & Motion) of Waka

Our tupuna developed many different types of waka to use for different purposes. Our job is to understand the pūtaiao behind why these different waka are designed they way they are.

The Land of the voyagers website has some fantastic images, videos and stories related to waka travel.

https://www.thevoyage.co.nz/en/video/37_Waka-Hourua-High-Tech-Travel 

Types of Waka

1. Visit the following site, use the information to copy and complete the table below in your pukapuka.

https://eng.keitemohiokoe.tki.org.nz/Overview-of-Physics/Canoes-1/Different-waka-for-different-roles 

2. Read the following short description of waka kōrari, then answer the questions below.

Waka pūhara or waka kōrari

These waka were constructed with seats for several people. To give the waka strength, so that it would not break up in the sea, the hull was made from a frame of wooden poles. These wooden poles formed two keels (part of a boat that runs along the length of the hull from the front of the boat to the back) which gave the waka a flat bottom. The waka was also light enough to be easily carried.

Ētahi pātai mā ngā ākonga

a) Why do you think the waka kōrari hull has a flat bottom? 

b) What would happen to the waka if wooden poles were not used in its construction?

c) Why was it important that the waka kōrari was light?

Structure of Waka

Paste one of the diagrams of a waka into your pukapuka, give it an appropriate title, and write a sentence for each feature describing the purpose of the feature.

Waka Hourua - why are they so special?

Pūtaiao ideas about forces

1. Read the summary info below, highlight the key Pūtaiao kupu in the passage of text. (This first sentence is done for you)

As a waka glides through the vast Pacific Ocean, it experiences a delicate balance of forces that govern its movement. The thrust force propels the waka forward as the paddlers pull on their oars, pushing against the water3. Simultaneously, the drag force opposes this motion, created by the resistance of both air and water against the moving vessel3.

The weight of the crew and cargo exerts a downward force on the waka due to gravity, while the buoyancy of the water provides an upward support force, keeping the craft afloat3. In the case of a waka hourua (double-hulled canoe), this design enhances stability and allows for ocean voyages across great distances25.

When sailing, the wind catches the waka's sail, creating an additional thrust force. The skilled navigator must read the wind, waves, and celestial bodies to harness these forces effectively5. As the waka encounters waves, it flexes and moves with them, its lashed construction allowing it to absorb the ocean's power5.

This intricate interplay of forces allows the waka to traverse the mighty ocean, connecting the peoples of the Pacific and carrying their stories across generations14. 

Physics about Waka - what makes them move, float, sink, etc.

Learning outcome

I will be able to:

• describe the forces acting on a waka

• identify forces that are balanced

• identify forces that are unbalanced

• identify the relationship between weight force in a waka and drag force

• explore the relationship of thrust and drag forces on the resultant force

1. Waka forces

In designing waka ama for racing there are many things that need to be considered. This is because there are lots of forces that act upon the waka. Forces can either push or pull. They can decide whether you win or lose a race. There are four forces that act on a waka:

Weight: The downwards pull of gravity on an object.

Support: The upwards push to support an object.

Thrust: The force that makes an object move.

Drag: The force opposing the motion of an object.

2. Applying forces

Visit this site to complete the interactive about forces on a waka.

https://eng.keitemohiokoe.tki.org.nz/Overview-of-Physics/Canoes-2/Interactive-Waka-forces-Level-4 

3.Balanced and unbalanced forces

Balanced forces

When an object is not moving the forces acting on the object are balanced.

Scenario; The weight force of the paddlers is equal to the support force of the waka on the water when they get into the waka before they paddle.

Qn 1: Is the waka moving? Are the forces balanced or unbalanced?

Qn 2: What do you think the relationship is between the person’s weight force and the support force of the waka? Are these forces balanced or unbalanced?

When an object travels at a constant speed the forces are also balanced. If a waka ama team were paddling at 10km/hr (fast walking speed), the force of the paddles pushing against the water would be the same as the drag forces of the water pushing against the hull and the wind pushing against the people.

Scenario; thrust force of the paddlers is equal to the drag force of water and wind, the boat is travelling at a constant speed.

Qn 1: Is the waka moving? Are the forces acting on it balanced or unbalanced?

Qn 2: What would you need to do to make the waka speed up (accelerate) or slow down (decelerate)?

 Unbalanced forces

When the forces acting on an object are unbalanced, the object will either accelerate or decelerate.

When a waka ama team start a race the thrust force from the paddlers will be much greater than the drag force of water and wind. This means that the waka ama will accelerate. Because the thrust force is greater than the drag force, the forces are unbalanced.

Scenario; the waka ama boat has capsized due to the weight of the paddlers not being evenly distributed.

Qn 1: Were the forces acting on the waka balanced or unbalanced? Which force was greater?

Measuring forces

We measure force using a unit called the newton or N for short. Ten newtons is equal to one kilogramme.

Qn 1: Can you estimate your approximate weight force in newtons? (Weight Force in Newtons = Mass in kg X 10)

Qn 2: If you climbed into a waka ama, what would be the support force of the waka in newtons?

Waka Race Day Interactive

1. Go to this site to complete the interactive activity about racing waka, 

https://eng.keitemohiokoe.tki.org.nz/Overview-of-Physics/Canoes-2/Interactive-Race-Day 

2. Copy and complete the table with your results into your pukapuka

3. Answer the following questions in your books.

Race Day Questions

Q1 If the thrust force (or paddling force) is bigger than the drag force, the waka ama will go forwards. If the drag force from the wind blowing onto to the front of the waka ama was bigger than the thrust force, then the waka would go backwards. What do you think would happen to the waka ama if the drag force and thrust force were the same?

a)    The waka would go backwards

b)    The waka would go sideways

c)     The waka would stay in the same position

d)    The waka would go forwards

Q2 Sometimes in physics it easier to explain things in equations rather than sentences. What do you think the equation would be for the resultant force?

a)    Resultant force = weight force – thrust force

b)    Resultant force = thrust force x drag force

c)     Resultant force = thrust force - drag force

d)    Resultant force = thrust force + drag force

Q3 What do you think would be the equation for the support force for the waka ama?

a)    Support force = weight force – thrust force

b)    Support force = drag force

c)     Support force = weight force

d)    Support force = weight force + drag force

Q4 Which equation would represent the waka ama at a constant speed?

a)    Thrust force = drag force

b)    Thrust force = weight force x drag force

c)     Drag force = weight force

d)    Thrust force = weight force + drag force]

Waka Construction

Use the information below about how waka were traditionally created to give you ideas about your own mini waka model construction.

Waka, traditional Māori canoes, were constructed using a variety of materials and techniques, with the process varying depending on the type and size of the vessel. The construction of a waka was a complex and time-consuming process, often taking several years to complete4.

Materials

The primary materials used in waka construction were:

• Wood: Large trees such as tōtara, kauri, mangeao, rimu, kahikatea, and mataī were commonly used2. Tōtara was the most frequently used, while kauri was prevalent in the north2.

• Flax: Used for lashings (aukaha) to bind various components together3.

• Bull kelp: Used in some types of waka for flotation2.

Construction Process

1. Tree selection and felling: A suitable tree was chosen and felled under the guidance of expert carvers (tohunga whakairo)3.

2. Initial shaping: The log was roughly hollowed out near where it fell, creating the hiwi (hull)2.

3. Transportation: The roughed-out hull was hauled to a more convenient working place2.

4. Detailed carving: Expert carvers shaped the waka, often incorporating intricate designs and symbolic patterns3.

5. Assembly: For larger waka, such as waka taua, the main components were:

   • Takere (hull): Carved from a single large log3.

   • Rauawa (topstrakes): Added to increase freeboard and improve seaworthiness2.

   • Tauihu (prow) and Taurapa (sternpost): Elaborately carved decorative pieces attached to the bow and stern2.

   • Kiato (thwarts): Crossbeams providing structural support and seating3.

   • Haumi (connecting pieces): Joints connecting different sections of the waka3.

6. Lashing: Components were lashed together using aukaha (canoe lashings) made from materials like harakeke (flax)3. This method allowed the waka to flex with the waves, absorbing pressure in heavy seas1.

7. Finishing touches: Additional elements such as bailers (tatā, tīheru, tā wai) and anchors were added2.

The construction process was accompanied by various ceremonies and rituals, ensuring the waka's spiritual significance as well as its physical form34

Making Waka

Learning Outcome

I will be able to: 

• choose materials for my waka kōrari that make it easy for the waka to float

• make a  waka kōrari

• include in the design of my waka kōrari items that make the waka stable in the water.

Exploring floating and sinking by making a waka kōrari

In this activity you will be making your own waka kōrari using materials that are easily obtained. You can choose to make your waka using modern or natural materials.

Materials;

Ma

• Drinking straws

• Four 2cm squares of bubble wrap

• Four wooden kebab sticks or skewers

• Sticky tape

• Scissors

• Thick straw or thin pieces of kōrari

• Seaweed air bladders

• Two flexible twigs (30cm long)

• Thin strips of harakeke

• Scissors

Your waka kōrari will be a model that is between 22 and 30cm long. It will need to be stable in choppy water and difficult to capsize (tip over). It will need to have at least one seat with room for a person’s legs. Feel free to use a toy person as your cargo.