Airboat - Community Science Workshop Network

Airboat Category: Physics: Electricity, Motors, Force & Motion Type: Make & Take Rough Parts List: 1 2 4 2 4 2 Battery Motors Connection wires Brass fasteners Paper clips Medium to large propellers Electrical Tape Knife Glue gun Styrofoam Materials to elevate motors How To: Cut a shape for the bottom of the airboat.
Build platforms for the propellers. Make propellers by gluing card stock to a bit of glue stick and attach one to each motor. Build a battery pack. © 2011 Watsonville Environmental Science Workshop. All Rights Reserved worldwide. When linking to or using WESW content, images, or videos, credit MUST be included. Connect each motor to the battery pack. Airboats can be designed in many ways. The model above uses plastic bottles, popsicle sticks, styrofoam, and cardboard. Backside of model #2. Test the airboat and watch it move across the water. Underside of model #2. Fine Points: → The propellers should be up high enough that they do not hit the water when they spin. → Place the propellers far apart so that they do not hit each other when they spin. → One motor is enough, but two can give more thrust and more control. A tethered remote control can also be created on this project. © 2011 Watsonville Environmental Science Workshop. All Rights Reserved worldwide. When linking to or using WESW content, images, or videos, credit MUST be included. Concepts Involved: •
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Force and motion Density Friction Newton’s Laws of Motion: − An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force. − Acceleration is produced when a force acts on a mass. The greater the mass of the object being accelerated the greater the amount of force needed to accelerate the object. − For every action, there is an equal and opposite reaction. Focus Questions: 1.
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Drop your boat into the water. Does it move on its own?
Turn on the propeller. How far will the boat travel before stopping?
Why doesn’t your boat sink?
Try building a boat out of wood, paper, and cardboard. Does your boat float? Which material builds the
best boat?
5. Stack high-density objects like nails, rocks, or coins onto the boat. How well does the boat float and move
with the additional weight?
Elaboration: An airboat is basically a boat propelled by a giant fan. Since an airboat’s propellers are placed above the water, the base of an airboat can be made completely flat. This allows the airboat to travel over places where normal boats cannot go, such as shallow rocky water, swamps, ice and sometimes even grass. Newton’s Laws of Motion help us to understand how airboats move. Newton’s 1st Law says that an object at rest will remain at rest unless acted on by an unbalanced force. When dropped into the water, the airboat does not move on its own, it needs the force of the propellers to move around. After the propellers have been turned on and the airboat has started moving, it will keep moving until it hits a wall or something gets in its way (an unbalanced force). The styrofoam airboat model moves quickly through the water because it is made of lightweight material. If the airboat were made of wood or metal, bigger propellers would be needed to move the airboat at the same speed as the styrofoam model. This follows Newton’s 2nd law: the greater the mass of the object being accelerated, the greater the amount of force needed to accelerate the object. Newton’s 3rd Law tells us that for every action, there is an equal and opposite reaction. The propellers of an airboat have been set up so that when they move, they throw air behind the boat. The action of the propellers creates an equal and opposite reaction pushing the boat forward. Changing the size of the
propellers on the styrofoam model may also influence the speed of the airboat.
Links to k-­‐8 California State Standards: Grades k-­‐8 Standard Set Investigation and Experimentation © 2011 Watsonville Environmental Science Workshop. All Rights Reserved worldwide. When linking to or using WESW content, images, or videos, credit MUST be included. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other strands, students should develop their own questions and perform investigations. Grade 2 Standard Set 1. Physical Sciences The motion of objects can be observed and measured. 1.a. Students know the position of an object can be described by locating it in relation to another object or to the background. 1.b Students know machines and living things convert stored energy to motion and heat. 1.c Students know the way to change how something is moving is by giving it a push or pull. The size of the change is related to the strength, or the amount of force, of the push or pull. 1.d Students know energy can be carried from one place to another by waves, such as water waves and sound waves, by electric current, and by moving objects. 1.e Students know objects fall to the ground unless something holds them up. Grade 3 Standard Set 1: Physical Sciences (Energy and Matter) Energy and matter have multiple forms and can be changed from one form to another. 1.b Students know sources of stored energy take many forms, such as food, fuel, and batteries. 1.c. Students know machines and living things convert stored energy to motion and heat. 1.d. Students know energy can be carried from one place to another by waves, such as water waves and sound waves, by electric current, and by moving objects. Grade 4 Standard Set 1: Physical Sciences Electricity and magnetism are related effects that have many useful applications in everyday life. 1.a. Students know how to design and build simple series and parallel circuits by using components such as wires, batteries, and bulbs. 1.g Students know electrical energy can be converted to heat, light, and motion. Grade 8 Physical Standards Standard Set 2. Forces: Unbalanced forces cause changes in velocity. 2.a. Students know a force has both direction and magnitude. 2.b. Students know when an object is subject to two or more forces at once, the result is the cumulative effect of all the forces. 2.c. Students know when the forces on an object are balanced, the motion of the object does not change. 2.d. Students know how to identify separately the two or more forces that are acting on a single static object, including gravity, elastic forces due to tension or compression in matter, and friction. 2.f. Students know the greater the mass of an object, the more force is needed to achieve the same rate of change in motion. Grade 8 Standard Set 8. Density & Buoyancy All objects experience a buoyant force when immersed in a fluid. 8.c Students know the buoyant force on an object in a fluid is an upward force equal to the weight of the fluid the object has displaced. 8.d Students know how to predict whether an object will float or sink. Grades 9-­‐12 Chemistry Standard Set 4: Gases & Their Properties 4.a. Students know the random motion of molecules and their collisions with a surface create the observable pressure on that surface. Grade 9-­‐12 Physics Standard Set 1. Motion & Forces Newton’s laws predict the motion of most objects. 1.b Students know that when forces are balanced, no acceleration occurs; thus an object continues to © 2011 Watsonville Environmental Science Workshop. All Rights Reserved worldwide. When linking to or using WESW content, images, or videos, credit MUST be included. move at a constant speed or stays at rest (Newton’s First Law). 1.d Students know that when one object exerts a force on a second object, the second object always exerts a force of equal magnitude and in the opposite direction (Newton’s Third Law) 1.f Students know applying a force to an object perpendicular to the direction of its motion causes the object to change direction but not speed. Grade 9-­‐12 Physics Standard Set 4. Waves: Waves have characteristic properties that do not depend on the type of wave. 4.a Students know waves carry energy from one place to another. 4.d Students know sound is a longitudinal wave whose speed depends on the properties of the medium in which it propagates. Grades k-­‐12 Mathematical Reasoning: 1.0 Students make decisions about how to approach problems: 1.1 Analyze problems by identifying relationships, distinguishing relevant from irrelevant information, sequencing and prioritizing information, and observing patterns. 1.2 Determine when and how to break a problem into simpler parts. 2.0 Students use strategies, skills, and concepts in finding solutions: 2.1 Use estimation to verify the reasonableness of calculated results. 2.2 Apply strategies and results from simpler problems to more complex problems. 2.3 Use a variety of methods, such as words, numbers, symbols, charts, graphs, tables, diagrams, and models, to explain mathematical reasoning. 2.5 Indicate the relative advantages of exact and approximate solutions to problems and give answers to a specified degree of accuracy. 3.0 Students move beyond a particular problem by generalizing to other situations: 3.1 Evaluate the reasonableness of the solution in the context of the original situation. 3.2 Note the method of deriving the solution and demonstrate a conceptual understanding of the derivation by solving similar problems. 3.3 Develop generalizations of the results obtained and apply them in other circumstances. © 2011 Watsonville Environmental Science Workshop. All Rights Reserved worldwide. When linking to or using WESW content, images, or videos, credit MUST be included.