Ship Wrecked! Outcome: 5-3-14: Use the design process to construct a prototype containing a system of two or more different simple machines that move in a controlled way to perform a specific function. Materials: writing utensil research materials (library, internet, etc.) various materials for constructing prototype (to be determined by individual students) Teacher s Instructions: 1. Make a class set of pages 2-9. For this activity students may work individually or with a partner. Page 10 is a peer assessment sheet. Make enough copies of page 10 so that each student can fill one out for each student or pair of students that will be presenting. Page 11 is for teacher assessment. Make one copy for each student or pair of students that will be presenting. 2. Explain to the class that they will be solving a problem using the design process. The task is to design and create a fishing tool and present their ideas to the rest of the class. 3. Hand out pages 2-9 to each student. Page 2 describes the problem that students will be required to solve and the list of criteria for their designs. 4. Pages 3-5 outline the design process. Students will use this log to document their progress throughout the design process. This will be submitted for evaluation after presentations. 5. This project requires students to do some research. Pages 6-8 contain background information to help them get started. 6. Students will use page 9 to complete a self assessment after they have completed their design and presented it to the class. 7. Students will use page 10 to complete peer assessments during/after each presentation. Teachers will use page 11 for evaluating projects/presentations. Teacher Background Information: For background information on the Design Process, see pages 3-5. For background information on simple machines and fishing tools made from simple machines, see pages 6-8. 1
Ship Wrecked! Try and solve this problem! Your boat has been capsized in bad weather and you are on a small island that used to be a fishing camp. Rescue off the island will be in a few days after the weather conditions improve. Survival will depend on designing a device to catch fish from shore. The criteria that you have to follow are: the device must be built using only recycled material which can be found in the old fishing hut. There is no fishing equipment, just materials that you may be able to fasten together; the device must contain at least two or more simple machines; and one person alone must be able to demonstrate how it will be used. 2
Design Process Log Using the Design Process to Solve a Problem Name: Step 1: Identify a Practical Problem to Solve What problem are you trying to solve? What is the intended purpose of your design? (What is your design supposed to do?) Step 2: Research What do you already know about this kind of device? What other information did you find about this kind of device? What materials will you need to construct this device? Step 3: Develop Criteria to Evaluate a Prototype What is the criteria that your device must meet? (Hint: see page 2.) The class may also include additional criteria (e.g. function, efficiency, aesthetics, waste, etc.). 1. 2. 3. 4. 5.. 6. 3
Step 4: Construct a Prototype Sketch your design inside the box below. Label all the parts of your design. Once you have sketched your design, construct a prototype of your design. (Hint: a prototype is an example.) Step 5: Test a Prototype Use the scale to rate your device according to the criteria listed in Step 3. 1. 2. 3. 4. 5. 6. 4
Step 6: Identify and Make Improvements Look at your scores from Step 5. Did you score lower than 3 on any of the criteria? Yes No If yes, list the criteria in the space provided below and describe how you will improve your design to meet this criteria. Area that needs improving My Improvements Step 7: Communicate and Reflect on Solution Use the space below to write a brief description of your design, how the device works, why you chose to construct it the way you did, and how it solves the initial problem. Remember, you will be presenting this to your classmates so be prepared to show your design and demonstrate how it works. 5
Simple Machines A simple machine is a tool that makes work easier. It has few or no moving parts and it requires some form of energy, or effort, to work. There are six simple machines: lever wheel and axle wedge inclined plane screw pulley A lever is a board or bar that rests on a turning point. This point is called the fulcrum. An object that a lever moves is called the load. The closer the load is to the fulcrum, the easier it is to move. An example of a lever is a see-saw. A see-saw has two loads, the people on either side of the see-saw. Another example of a lever is a hammer when it is used to pull out a nail. The load in this case is the nail. An inclined plane is a flat surface that is higher on one end. It is used to move an object to a lower or higher place. When it moves a load to a lower place it uses the force of gravity. An example of an inclined plane is a slide. The load (a person) uses the slide to get from the top of the structure to the bottom of the structure. Another example of an inclined plane is a ramp. Ramps make it easier to move things to lower or higher ground. A wheel and axle make up another simple machine. The axle is the rod that goes through the wheel and lets the wheel turn. Wheels and axles make it easy to move things from place to place. Imagine that you are walking your bicycle across the street. Now imagine that your bicycle does not have wheels. Which way is easier? A screw is a simple machine that is made from another simple machine. It is an inclined plane that winds around itself. It is used to raise or lower objects or to hold things together. For example, the screws on the inside of a lid and the outside of a jar works to fasten the lid to the jar. A light bulb is another example of a screw. A wedge is used to push two objects apart. It s made of two inclined planes that meet and form a sharp, narrow edge. The sharp edge is inserted between objects. As pressure is applied and the wide end pushes through, the objects come apart. An axe is an example of a wedge. A pulley is made out of a wheel and a rope. The rope fits inside a groove in the wheel. One part of the rope is attached to the load. When you pull the other side of the rope, the wheel turns and the load moves. Pulleys make the work of moving heavy loads much easier and are useful for moving things to hard to reach places. Flag poles, cranes, and window blinds all use pulleys to work. 6
Simple Machines and Fishing Fishing Rod and Reel Probably the most familiar method of fishing, the rod and reel uses a lever and a pulley. A fishing rod is an example of a lever. The fulcrum is at the end where the angler s hand is holding onto the rod. The load is the lure or hook that is cast out in the water. The load can also be the fish that the angler is lucky enough to catch. The effort, which is applied in the middle of the rod, comes from reeling in the fishing line. However, the lever also acts to increase the speed and distance of the load (lure) as it is cast out over the water. The longer the fish rod, the greater the distance that the lure can be cast. The reel on the fishing rod is actually a wheel and axle. The reel has a wheel which is attached to a central axle that moves the wheel when it is turned. The fishing line winds or unwinds around the axle, making a pulley. The reel also has a crank handle that makes it easier to wind the fishing line. Ice Fishing Many Manitobans like to fish in the winter. In winter, anglers do not need a long rod because they do not need to cast their line. Instead, they fish through a hole in the ice. In this case, a short lever suffices. Anglers use what is called a tip-up, which is another example of a lever. In this case the rod, or lever, acts more like a see-saw. The fulcrum is in the middle and the lever is weighted on one end so the other end sticks up in the air. When a fish (the load) bites, it pulls down the high end, causing the weighted end to pop up and signaling to the angler that something is on the line. But wait! How do anglers make a hole in the ice? They use an ice auger. An auger is an example of a screw, which is a more complex version of an inclined plane. In this case, the inclined plane is cut in a spiral shape around a metal shaft. 7
Commercial Fishing Manitobans do not only fish for recreation. Some are commercial fishers who catch the fish that you buy in the grocery store. They fish for a living. The fishers fish with gill nets. Gill nets are like underwater fences. Fish are caught when they try to swim through the mesh, which entangles their gills. The nets vary in length, depth, and size of mesh. The mesh size determines the size of fish that can be caught. Each net is about 80 metres long with plastic floats attached to the top line of the net and lead weights along the bottom line. When the net is full of fish it is very heavy and difficult to lift out of the water. The large commercial boats (which can be up to 50 feet long) have a motorized net lifter at the front of the boat (called the bow ) that works much like a pulley. It resembles a reel on a fishing rod, only much larger. Commercial Fishing in Winter Commercial fishers also fish in winter under the ice. How do they do it? Well, just like an angler, they use an auger to drill holes through the ice, only their augers are much bigger. Once the holes are drilled, they set their nets under the ice using a jigger. The jigger is a dart-shaped plank about six feet (1.8 metres) long. It has a steel-tipped wooden arm running through a slot and hinged to a steel rod. A long rope is attached to the rod. To set a net, a jigger is placed through a hole cut in the ice. The jigger is positioned so that the steel-tipped arm sticks up against the underside of the ice at the water s surface. When all is ready, the operator pulls on the rope (applies force). The rope is attached to the metal rod (the lever) on the jigger. When pulled, the rope applies pressure on the wooden arm, pushing it upwards and causing the steel tip to dig into the ice and propel the jigger forward approximately one metre. When the rope is released, the steel tip drops away and returns to its former position. The operator tugs the rope again and repeats the process until the jigger has moved from the first hole a distance equal to the length of the net. A second hole is then drilled and the jigger is removed. The rope trailing the jigger is tied to a gill net. As the rope is pulled, the net enters the water through the first hole and is pulled into position between the two holes. lake ice steel runners direction of jigger iron rod wooden arm steel tip slack line water 8
Student Design Process Self Assessment Student Name: I chose to make a... One success I experienced was... One problem I encountered was... If I did the project again I would... I would still like to learn more about... I think my design... 9
Student Design Process Peer Assessment Name of Student/Group: Name of Evaluator: What did the student/group make? What success did they have? What problems did they encounter? Were they able to solve these problems? Yes No If "yes, how? Rate the student/group on the following by circling the appropriate space. ("1" = poor, the lowest rating, and "5" = excellent, the highest rating.) 1. Aesthetic value of the device 1 2 3 4 5 2. Use of recycled materials 3. Effectiveness of the device 4. Presentation and knowledge about the device 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 10
Teacher Design Process Checklist Name of Student/Group Design Process (After student presentations, collect Design Process Log.) 1. Identifies/Understands the problem 2. Shows research for possible solutions 3. Develops/Identifies criteria for success 4. a) Provides labeled sketch/blueprint 4. b) Constructed a prototype 5. Tested prototype according to criteria identified 6. Identifies problems and makes improvements Other criteria 7. Presented and communicated results Used recycled materials Two or more simple machines used Can be maneuvered by one person 11