Hovercraft - Where STEM-Rich Making Begins – …Water"is"one"place"where"a"hovercraft"can"travel"smoothlyK"aslongastherearen’tlargeoceanwaves!"" Roads"are"smooth"too,butbeforeworkingonaroad

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Hovercraft Category: Physics: Force & Motion, Fluids, Circuits

Type: Make & Take

Tools:

How To:

Find and mark the center of the plate.

Mark a line across a cup so that one half is

slightly smaller than the other half.

1 Paper plate 2 Paper cups 1 Motor

10-‐12’ Electrical wire 2 Small paper clips 2-‐4 Batteries 1 Paperclip ¼” Hot glue stick

Scissors Box Cutters Masking Tape Electrical Tape Marker Ruler or straight edge Hot glue gun


One half should be smaller than the other. Place the larger half-‐cup along the center

line of the plate. Mark where the two sides of the cup touch the plate.

The markings should look like this. Cut along the centerline of the plate – only

between the cup lines!


Cut along the sidelines of the cup. Only cut where the lines are marked – not to the

edge of the plate!

Cut a slit along the centerline of the flap.

Tape the cup to the plate. Tape the flap of paper plate

onto the inside edge of the cup.


Push the hot glue piece onto the motor

shaft.

Draw a straight line along the side of a cup, use this as a reference line. Draw two

diagonal lines across the cup.

Cut along the two diagonal lines to make a

propeller. Hot glue the propeller onto the end of the

glue stick on the motor. Test the propeller to be sure it blows air towards the motor. Cut the electrical wire into two long pieces. Connect one end of each wire to the motor.


Glue the motor onto the top edge of the

cup. Tape the wires onto the top of the cup to keep them from tangling.

Wrap foil around the free end of one wire. Tape the foil to the negative terminal of a

battery.

Wrap the free end of the second wire around a paperclip that has been bent

open.

Tape the paperclip near the positive terminal of a battery. Position the paperclip so it does not touch the battery but can be pressed by your finger to make contact.


Place your hovercraft on a smooth flat surface. Press the paperclip onto the

battery pack and watch your hovercraft fly around.

Fine Points:

If the plate is warped or bent, the hovercraft may not hover. You can balance the hovercraft by gluing pennies on the plate where it seems to rise the highest. If your batteries are weak, put three or four in series. The propeller’s blades should be bent such that the wind generated blows back into the cup and over

the top of the cup. The propeller should be as close as possible to the mouth of the cup to avoid losing wind to the side. Tape or route the wires so that they are not tangled with the propeller.

Concepts Involved:

• Lift is the force that directly opposes the weight of a flying object.

• Propulsion moves or pushes an object forward.

Elaboration:

A hovercraft is a vehicle that glides over a smooth surface by hovering on an air cushion. Hovercrafts will

float when the air pressure under the “skirt”, in this case the rim of the plate, is great enough to support

the weight of the hovercraft. When there is enough air to lift the hovercraft, a bit of extra air begins to

escape and its escape route is all around the rim of the plate. So the air escaping from under the plate

provides a cushion all around for the hovercraft to float on, allowing the hovercraft to glide freely upon

the smooth surface below.


Because hovercraft can only travel on smooth surfaces, there are not many places where a hovercraft can

go. Water is one place where a hovercraft can travel smoothly-‐ as long as there aren’t large ocean waves!

Roads are smooth too, but before working on a road-‐worthy hovercraft consider two things: stopping and

turning. If a hovercraft isn’t touching the road then it is really hard to stop or turn accurately, which may

make for a dangerous road vehicle!

Links to k-‐8 California State Standards:

Grades k-‐8 Standard Set Investigation and Experimentation 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.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. Grade 8 Standard Set 2: Forces 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. 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.


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.

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Hovercraft - Where STEM-Rich Making Begins – …Water"is"one"place"where"a"hovercraft"can"travel"smoothlyK"aslongastherearen’tlargeoceanwaves!"" Roads"are"smooth"too,butbeforeworkingonaroad