Friction
What does friction do as a force?
it increase the force or energy you need to move one object across another
what does the number of mechanical advantage represent about a machine
how much force input into the machine is multiplied
what does it mean for a machine to be efficient?
most of the work you put into the machine is preserved
What is a simple machine
a device that changes the amount of force, or direction of force, or distance an action covers
What kind of simple machine is a broom?
a lever
what makes one thing have more friction than another?
how rough its surface is
how is actual mechanical advantage calculated?
the amount of force the machine outputs (acts with) divided by the amount of force put into a machine (how much force you apply)
how is mechanical efficiency written down (what unit does it use)
a percentage
how do simple machines increase the amount of force you apply?
by making you work longer / over more distance
what two simple machines make up a wheelbarrow?
a lever and wheel
by making it smoother / adding lubricant
How is Ideal Mechanical Advantage calculated?
by dividing the amount of distance you put into a machine (such as the length of a ramp) by the amount of distance that the machine is replacing (the height of the ramp)
how can you increase the efficiency of a machine
remove some of the friction from its parts
What is an example of a simple machine makes the user work harder so they can cover more area
lever (broom) hammer, gear,
what is a machine that exchanges applying more force in exchange for moving something further than you moved?
A broom, a hammer, a sword, a rake, etc
What are the three types of friction?
sliding, static (non moving), and rolling
What is the actual mechanical advantage of a machine that outputs 100 Newtons of force when you apply 50 Newtons to it?
2 : 1 Actual Mechanical Advantage
what is the efficiency of the following machine?
You put in 100 joules of work into the machine, and it generates 75 joules of work on whatever weight it is moving
75% efficiency
what is an example of a simple machine that can change the direction of force?
Why do engineers apply grease to factory equiptment?
to reduce friction and wear
What type of friction is the weakest?
Rolling friction
What is the ideal mechanical advantage of a lever that is 1 meter long, that moves a weight 10 centimeters?
10 : 1
you have a pully that you exert 400 joules of force on, on the opposite side of the pulley a weight of 40 newtons is lifted 5 meters. What is the efficiency of this machine?
50% efficiency
what are all 6 simple machines
wheel, screw, lever, inclined plane, wedge, pully
What were some simple machines designed by the ancient Greeks?
Block and Tackle, Gears, Pneumatics, Steam Engine, Gimble