Simple Machines
the use of force to move an object over a distance
work
For work to be done, an object has to
move
When using a simple machine, the number of forces applied are
1
a bar that tilts or pivots on a fixed point
lever
a fixed point on a lever
fulcrum
What decreases the force needed on a lever?
Moving the load closer to the fulcrum
lever with the load between the force and the fulcrum What kind of lever? lever with the load between the force and the fulcrum
Second Class
lever with the fulcrum between the effort and load What kind of lever?
First Class Lever
lever with the effort between the force and load What kind of lever? lever with the effort between the force and load
Class 3
a simple machine made of a wheel and a rod that turn together
Wheel and axle
a rod between two wheels
axle
A big wheel makes the turning force easier, but it will require a longer
distance
a surface
plane
a slanted surface
Inclined plane
What is easier? Lifting something straight up Or Pushing up an inclined plane
Inclined Plane
Which is easier? Steep slope Flatter slope
Flatter slope harder easier
an inclined plane wrapped around a post
Screw
Inclined plane requires a longer
distance
made of two inclined planed put back to back
wedge
A wedge can be used to _____ and ______
Cut and lift
A pulley can change the _______ of a force.
direction
Adding pulleys can _____________ the force needed
reduce
Which two simple machines are most alike?
screw and inclined plane
Which simple machine would be best to slice carrot?
wedge
Which of the following changes the direction of a force but not the amount of force needed to do work?
Single pulley
How do we use a pulley everyday at school?
flagpole
What is transferred when work is done?
energy
Which part of the lever supplies the force to move something?
effort
Which part of the lever is the part you are trying to move?
load
What are the two types of forces?
Push and Pull
This is necessary to get something moving
force
How many classes of levers are there
3
These two simple machines make a screw
Wheel and Axle and Inclined Plane
If you use a screw driver to open a can of paint, you are using it mostly as a
lever
If you weigh 80 pounds, and you are lifting an object with one pulley, the object has to weigh how much?
80 pounds or less