what is a lever?
a rigid bar that allows the application of either increased force and/or speed
what is ARF
- A: axis - point of rotation
- R ( a resistance - load to be overcome)
- F (a force - the point where force is applied
what are 3rd class levers made for?
to amplify speed
where is the force always?
between the axis and resistance
what is mechanical advantage?
a measure of how much a lever amplfies force
a lever with a mechanical advantage greater than 1…
will increase force = requires less effort to move a resistance
an equal mechanical advantage..
is balanced with speed and force
a lever with a mechanical advantage less than 1
will increase speed = increased range of motion and angular speed
mechanical advantage equation
mechanical advantage = force arm/resistance arm
why are all 3rd class levers speed magnifiers?
because they all have longer resistance arms than force arms
the longer the resistance arm and further below 1 the mechanical advantage is..
the greater speed that can be produced
linear speed equation
linear speed = angular velocity x moment arm (distance from axis to end of lever)
