MECHANICAL SYSTEMS  Introduction SPH4C COLLEGE PHYSICS MECHANICAL SYSTEMS  Introduction

Mechanical Systems When you grasp your pen and lift it upward, your arm is acting as a simple machine called a lever. To form compound machines, like the artificial arm shown, simple machines are linked together. Artificial limbs share some of the features found in bicycles, robots, cranes, and numerous other devices made of one or more simple machines.

Overall Expectations By the end of this unit, students will: analyze common mechanical systems that use friction and applied forces, and evaluate their effectiveness in meeting social or environmental challenges; investigate forces, torque, work, coefficients of friction, simple machines, and mechanical advantage, and interpret related data; demonstrate an understanding of concepts related to forces and mechanical advantage in relation to mechanical systems.

Big Ideas Concepts that students should retain long after this course are: Mechanical systems use force to do work.  The operation of mechanical systems can be described using mathematical relationships. Friction is a force that influences the design, use, and effectiveness of mechanical systems.  Mechanical systems can be used to address social and environmental challenges.

Getting Started: Useful Concepts & Skills CONCEPTS REVIEW A steel block can be placed in a wheelbarrow at position A, B, or C as shown. Which position would allow you to most easily raise the handle end of the wheelbarrow? Why?

Getting Started: Useful Concepts & Skills CONCEPTS REVIEW As shown below, ramps D and E lead to the same level above the ground. Would it be easier to push a wheelchair up ramp D or E? Explain your choices.

Getting Started: Useful Concepts & Skills CONCEPTS REVIEW When a wrench is used to take a nut off a wheel, what do you think the turning effect depends on?

Getting Started: Useful Concepts & Skills CONCEPTS REVIEW 4. Is it easier to break (by hand) a short pencil or a long pencil? Why?