2. Work
Occurs when a force acts on an object to move it some
distance (displacement) from the start point
Work = Force x Distance
Measured in joules (J), which is the same as Newton-meter
4. Simple Machines
Simple tools used to make work easier
Machine
A tool used to make work easier
Compound Machines
Consists of two or more simple machines put together
5. 03
How do Machines Help Us?
Transfer force from one place to another
Increase the amount of force applied on a certain task
Change the distance, speed, and direction of the
force
Note: A machine cannot increase both force and distance
at the same time.
6. Forces Involved in Using a Machine
Effort Force
The force applied on the machine
Work input
Output Force
The force exerted by the machine on the load that needs to be moved
Work output
7. 05
Example:
The man exerts an
input force (effort)
which is "multiplied"
by the pulley, resulting
to output force that
can lift the heavy
elephant.
8. 06
Mechanical advantage
Produced by a machine which only needs a small effort force
but has an increased output force
Can be computed by dividing the output force by the input force
The closer the work output is to the work input, the more
efficient a machine is. But no machine is 100% efficient.
9. Basic Types of Simple Machines
Lever
Wheel and Axle
Pulley
Inclined Plane
Wedge
Screw
1.
2.
3.
4.
5.
6.
25. A grooved wheel that
turns around an axle
which is held in place
by a mounting bracket
A rope or wire moves
along the wheel's
circumference
Used to pull up objects
Pulley
28. Movable Pulley
Moves along
the rope or wire
Increase the
amount of force
but decreases
its distance
ziplines
weight
machines
elevator
cables
Examples: