TESLA Simple Machines 2010 The Wheel

The Big Idea of this Investigation A simple machine is a mechanical device that makes work easier by magnifying, modifying, transferring, or changing the direction of applied force. Simple machines are the elementary "building blocks" of which all complicated machines are made.

Knowledge We Will Build on From Prior Investigations Work = Distance X Force Force is a push or pull applied to an object. Friction is the number one enemy of simple machines. It increases the amount of force needed to do work.

ENGAGING SCENARIO For generations we have been faced with tasks that require us to move an object from one location to another, and we know from our previous investigation, that friction plays a major role in increasing the force required. Think about how challenging tasks would have been 100, 200, and even thousands of years ago when humans had to move large objects without modern machinery. The materials to build Stonehenge and the Great Pyramids were not moved with machines like we have today. Many people believe that the invention of the wheel was one of the most important inventions of all time. In this investigation you will need to gather and provide evidence of how a wheel can affect the amount of force needed to complete a task (work). What is the problem we need to solve? What do we need to investigate? For generations we have been faced with tasks that require us to move an object from one location to another, and we know from our previous investigation, that friction plays a major role in increasing the force required. Think about how challenging tasks would have been 100, 200, and even thousands of years ago when humans had to move large objects without modern machinery. The materials to build Stonehenge and the Great Pyramids were not moved with machines like we have today. Many people believe that the invention of the wheel was one of the most important inventions of all time. In this investigation you will need to gather and provide evidence of how a wheel can affect the amount of force needed to complete a task (work). What is the problem we need to solve? What do we need to investigate? Discuss ideas with a partner for a possible focus question. Your focus question should be connected to what the scenario wants us to do…

Focus Question (What is the problem?) How can a wheel affect the amount of force needed to complete a task (work). NOTEBOOK ENTRY

New Vocabulary Wheel: A disk that turns around an axis. NOTEBOOK ENTRY Wheels have evolved a great deal over time from solid wood rollers in 3300 B.C. to the high-tech, lightweight wheels of today.

Prediction (related to the focus question) Prediction: I predict that a wheel will/will not reduce the amount of force needed to move an object because ___________________.Prediction: Previous Knowledge Share experiences with wheels related to the focus question. NOTEBOOK ENTRY

Class Predictions (related to the focus question)

Preparing the Investigation We are going to test the force and work required to move a brick across a carpeted surface. Each group will be given a spring scale, 1 brick, a meter stick, and 5 wooden dowels. What are we going to change What are we going to keep the same NOTEBOOK ENTRY The surface we pull the object across Carpet vs. Carpet with Dowels The object: brick The spring scale The distance we pull the object

Collecting Data We need to keep track of our data and observations… Work on Three Different Surfaces NOTEBOOK ENTRY Method Force (newtons) Distance (meters) Work (joules) brick without dowels brick with dowels

Making Meaning Conference Which method of pulling the brick required the most work? Why do you think less force was required to move the brick across the dowels? What mechanical advantage to wheels provide?

Claims and Evidence I claim that…I claim this because… How can a wheel affect the amount of force needed to complete a task (work). NOTEBOOK ENTRY

Reflection/Conclusion Revisit your original prediction… Explain how the evidence did or did not support your original prediction? My prediction was accurate because….. I wish to revise my prediction because… What did you learn… What really surprised you… What new questions do you have… What would you like to know more about… NOTEBOOK ENTRY