machine that increases the force
applied for a task.
speed multipliers
requires a small movement of
an effort to produce a large
movement of a load
Lever
first-class lever
the fulcrum is positioned between the
effort and load
pliers, tin snips, hedge-cutters, scissors.
second-class lever
when the load is positioned
between the fulcrum and the
effort
a wheelbarrow, bottle
openers, paper
guillotines, and
nutcrackers.
third-class lever
when the effort is
positioned between the
fulcrum and load.
tweezers, tennis racquets, cricket bats.
A lever is a simple machine that is made of
a long rigid object (like a stick or metal rod)
Increase the size of the effort
that you can apply or reduce
the effort needed, making the
job easier
using a hammer as a lever reduces the size of
the effort needed to pull a nail from a piece of
wood.
pivot or fulcrum
Point about which lever rotates at
How do you get a job done ?
You apply a force known as effort.
Wheels
rim
outer edge of a wheel
axle
a rod or spindle (either fixed or rotating) passing
through the centre of a wheel or group of wheels.
results in a large force
apply a slow force
increases speed
a fan
Pulleys
change direction of a force
reduces effort force when multiple
pulleys are used
Gears
a wheel with teeth as rims
change direction of a force
increasing speed
bicycle gears, clock, hand drill
Inclined plane
a sloping ramp up which heavy loads can be
raised by ropes or chains.
zip
a device consisting of two flexible strips of metal or plastic
with interlocking projections closed or opened by pulling a
slide along them, used to fasten garments, bags, and
other items.
wedge
a piece of wood, metal, etc. having one thick end and
tapering to a thin edge, that is driven between two
objects or parts of an object to secure or separate them.