Torque & LeversRelationship between torque, force, and distance
torque
torque the turning effect on a rigid object around an axis
when a force is applied and causes an object to rotate, we say that a torque was applied
the symbol for torque is T and the units are newton-meters Nm
example
consider pushing a door on a hinge open
it will open easier if you push further away from the hinge
the hinge is the fulcrum in this situation (the point around
which the door
rotates)
calculating torque
2 factors control torque:1. the magnitude of the force (TαF)2. the distance from the fulcrum (Tαd)
this gives us the formula:
T = Fd
where F is perpendicular to d (at 90 degrees)
practice
practice problem #3 on page 83
torque on levers
2 torques can be calculated for a lever:1. effort torque (TE)
2. load torque (TL)
they can be written with the formulas:
TE = FE dE
and
TL = FL dL
practice
practice problem #10 on page 84
law of levers when an object is at rest, it is said to
be static
an object in static equilibrium is not rotating or moving
Law of Levers “to have static equilibrium, the effort torque must equal the load torque”
this balance results from the any clockwise torque being equal to any counterclockwise torque
law of levers
effort torque = load toque
or
TE = TL
or
FEdE = FLdL
these equations can be rearranged to solve for any variable
practice
practice problem #12 on page 86