SIMPLE MACHINES – has few or no moving parts and makes work easier
Idea
Explanation
(What is it? Use your own words.)
ramp (inclined plane)
A slanted surface used to raise an object.
Less force is needed to move an object over a longer
distance.
Lever – a bar that is free to First Class Lever – The fulcrum (pivot point) is in the
pivot, or move about a fixed middle and the load and effort is on either side.
point when an input force is **Makes work easier by multiplying the effort AND
applied.
changing direction.)
Second Class Lever – The fulcrum (pivot point) is at the
Fulcrum = the pivot point of end, with the load in the middle. ** Makes work easier
a lever.
by multiplying the effort force, but NOT changing
direction.
Third Class Lever – The fulcrum (pivot point) is at the
end, but the effort is in the middle. **Does not multiply
the effort force, only multiplies the distance.
screw
An inclined plane wrapped around a cylinder.
The closer the threads, the greater the advantage
wedge
An inclined plane that moves
Pulley – A chain, belt, or
Fixed – can only change the direction of a force.
rope wrapped around a
wheel.
Movable – can multiply an effort force, but cannot
change direction
wheel and axle – the axle is
a rod that goes through the
wheel which allows the
wheel to turn
efficiency
work
power
Block and Tackle – can multiply an effort force AND
change direction
A lever that rotates in a circle.
Combination of two wheels of different sizes – gears
Smaller wheel is termed the axle.
Can never be greater than 100% because some work is
always needed to overcome friction.
The product of the force applied to an object and the
distance through which that force is applied.
Force MUST act in the direction of the movement
How quickly work is done
Example showing it
(Draw and explain)
EX – Ramps, stairs, ladders, bath tubs
First Class Lever (EX – hammer, scissors, pliers, teeter-totter,
Second Class Lever (EX – nut cracker, wheelbarrow, crow bar
Third Class Lever (EX- pair of tweezers, staple puller, broom, fishing
pole, tongs, arm, shovel, rake, hitting a baseball, playing tennis,
lifting weights, etc)
EX – Bolts, augers, drill bits, screws
EX – Razor blade, knife, axe, zipper
EX. - Flag pole, blinds, stage curtain
EX. – Wheels on a car or bike, gears
Work output ÷ work input
Work = Force X Distance
Power = Work ÷ Time
Measured in WATTS
1 kilowatt = 1000 W