2 What is a Machine? Definition: any device that makes work easier by changing a forceWork is done whenever a force moves an object over a distance
3 How do machines make work easier? Machines change how the work is done byIncreasing the amount of force that is appliedIncreasing the distance over which the force is appliedChanging the direction in which the force is applied
4 Increasing force?The machine applies more force than the user but over a shorter distance
5 Increasing DistanceThe machine increases the distance over which the force is applied, but it reduces the strength of the force
6 Changing the direction of force The machine changes the direction of the force applied by the user
7 Simple vs. Compound Machines There are 6 types of simple machinesInclined planeLeverPulleyWheel and AxleScrewWedgeCompound machines combine two or more simple machines
8 Measuring the change in force How much a machine changes the input force is called its mechanical advantageRememberInput force = force you place on machineOutput force = force machine places on objectTwo types:ActualIdeal
9 Actual Mechanical Advantage Takes into account the amount of the input force that is used to overcome frictionDifficult to measure input and output forces
10 Ideal Mechanical Advantage Uses input and output distance instead of forceDoes not take into account friction and will always be greater than actual mechanical advantage
11 PracticeCalculate the ideal mechanical advantage for the incline plane shown above.
12 PracticeA force of 200 N is applied to a machine in order to lift a 1,000 N load. What is the mechanical advantage of the machine?A machine is designed to push an object with a weight of 12N. If the input force for the machine is set at 4 N, what is the mechanical advantage of the machine?
13 PracticeAn input force of 35 N is applied to a machine with a mechanical advantage of What is the size of the load this machine could lift (how large is the output force)?A machine is required to produce an output force of 600 N. If the machine has a mechanical advantage of 6, what input force must be applied to the machine?