120 likes | 125 Views
Mechanical Advantage. A machine is… A device that allows for easier and more effective work. Something that does not have to be complex. Something that does NOT decrease the amount of work that is done. So what exactly is a machine?. What do machines do to make work easier?.
E N D
A machine is… • A device that allows for easier and more effective work. • Something that does not have to be complex. • Something that does NOT decrease the amount of work that is done. So what exactly is a machine?
What do machines do to make work easier? • Machines change the amount of force YOU exert • Machines change the distance over which you exert your force. • Machines multiply either force or distance, or they change direction.
Input and Output Forces • Input force, sometimes called an effort force, is the force that you (the operator) exert on the machine • Output force, also known as resistance force, is the force exerted by the machine
Making your life easier! • The output force is ALWAYS larger than the input force. • Ask yourself… “What’s Easier?”
Which would you rather do? Lift a car… Or roll it up a ramp…
Multiplying Distance • When we multiply distance, the output force is greater than the input force. • Applying a force over a short distance: Your hands move a short distance and the bat moves a longer distance.
Neither force nor distance is multiplied Would you rather push and lift the blinds up or pull the string down to raise the blinds?
Mechanical Advantage • Also known as MA • Mechanical advantage- the number of times a force is exerted on a machine is multiplied by the machine Mechanical Advantage = Output Force Input Force • The equation compares input force versus output force
Ideal vs. Actual Advantage • Ideal MA = Expected MA • Actual MA = Expected MA – Friction … Will we ever have Ideal Mechanical Advantage?
So why can’t the ideal mechanical advantage ever be equal to the actual mechanical advantage? Friction Energy is converted to heat.