section 3- types of machined Flashcards
what are levers used for
to apply force to a load
what are the three classes of levers
fulcrum
load
input force
where is the input force located in the first class lever
left
what do first class levers always do
change the direction of the input force
what can first class levers be used for
increase force
increase distance
where is the input force located in the second class lever
the right
do second class levers change the direction of the input force
no
what allows you to apply less force than the force exerted by the load
second class lever
what happens when the output force is greater than the input force
you must exert the input force over a greater distance
where is the input force located in the third class lever
middle
do third class levers increase the input force or change the direction of the input force
no
is the output force less than the input force in the third class lever
yes
what is a simple machine that has a grooved wheel that holds a rope or cable
pulley
when a load is attached to one end of the rope from the pulley what is applied to the other end
input force
what is attached to something that does not move
fixed pulley
what pulley makes you pull down on the rope to lift the load up
fixed pulley
what pulley changes direction of the force
fixed pulley
what are attached to the object being moved
movable pulley
does a movable pulley change a force’s direction
no
what do movable pulleys increase
force and distance
what pulley is a fixed pulley and a movable pulley used together what is the pulley system called
block and tackle
what does the mechanical advantage of a block and tackle depend on
the number of rope segments
what is a simple machine conditioning of two circular objects of different sizes
wheel and axle
how can you find the mechanical advantage of a wheel and axle
by dividing the radius of the wheel by the radius of the axle
what is a simple machine that is a straight slanted surface
inclined plane
what is an example of an inclined plane
ramp
what happens when the ratio of an inclined planes length to its height
the greater the ma is
how can the mechanical advantage of an inclined plane be calculated
dividing the length of the inclined plane by the height to which the load is lifted
what is a pair of inclined planes that moves
wedge
what does a wedge apply
an output force that is greater than your input force
the longer the wedge is the ___________ the wedge is
thinner
what is required in a wedge
less input force
how do you find the mechanical advantage of an wedge
by dividing the length of the wedge by its greatest thickness
what is an inclined plane that is wrapped in a spiral around a cylinder
screw
what happens when a screw is turned
A small force is applied over the long distance along the incline plane of the screw
what is a A machine that is made of two or more simple machines
compound machine
is the mechanical efficiency of most compound machines high or low
Low
can to much friction damage the simple machines that make up the compound machine
ya
what is a simple machine that has a bar that pivots at a fixed point called the fulcrum
lever
