chapter 4: machines and mechanical systems 4.1 forces in machines
TRANSCRIPT
CHAPTER 4: MACHINES AND MECHANICAL SYSTEMS
4.1 Forces in Machines
Mechanical Systems and Machines Machine: a device with moving parts
that work together to accomplish a task Example: a bicycle
Machines are designed to do something useful
Machines have an input and an output Input: includes everything you do to make
the machine work Output: what the machine will do for you
Six Types of Simple Machines
Simple Machines
Simple machine: an unpowered mechanical device They work by manipulating forces
Most machines today are combinations of simple machines Bicycle: wheels and axles, levers, and gears
Complex machine: a machine with many different simple machines put together
Mechanical Advantage
Simple machines work by changing force and motion Force: an action that has the ability to change motion
Mechanical advantage: the ratio of output force to input force Remember: input is what you do to the
machine, output is what the machine does for you
MA = Fo Mechanical Advantage = Output
Fi Input
Simple Machines in the Human Body
The human body is made completely of simple machines
Joints = levers Hips/Shoulders = ball and socket Anything else you can think of?