Machines Made Simple

1
Machines Made Simple

• Chapter 14

2
Simple Machines

• Ancient people invented simple machines that
  would help them overcome resistance forces and
  allow them to do the work against those forces.

3
Simple Machines

• A simple machine is a machine that does work with
  only ONE movement
• Six basic types
• Designed to make work easier, faster, or to
  change the direction of the force
• Few or no moving parts
• Combine to form more complex machines (i.e.
  compound machines)

4
Compound Machines

• A machine made up of 2 or more simple machines is
  called a compound machine
• Examples scissors, pencil sharpener, car,
  microwave, oven

5
Inclined Plane
6
Inclined Plane

• An inclined plane is a flat, sloped surface
• Longer and less steep smaller force needed
• Shorter and more steep larger force needed
• EXAMPLES ramps, hillside roads, stairs

7
Wedge
8
Wedge

• A wedge is two inclined planes put together and
  has a cutting edge
• EXAMPLES axes, door stops, your front teeth,
  scissors, knife blades

9
Screw
10
Screw

• A screw is an inclined plane wrapped around a
  cylinder or post (inclined plane forms screw
  threads).
• A screw holds things together
• EXAMPLES jar lid, screw, drill bit

11
Lever
12
Lever

• A lever is any rigid/stiff rod or plank that
  pivots, or rotates, about a pivot point (called
  the fulcrum).
• EXAMPLES hammer, rake, nut cracker, tweezers,
  scissors, crow bar, broom

13
Pulley
14
Pulley

• A pulley consists of a grooved wheel with a rope
  or cable wrapped over it.
• A pulley changes the direction of the applied
  force.
• EXAMPLES used on flagpoles, used on sails on a
  boat, used in cranes

15
Wheel and Axle
16
Wheel and Axle

• A wheel and axle consists of two circular objects
  of different sizes that are attached in such a
  way that they rotate together.
• EXAMPLES a fan, ferris wheel, doorknob, car
  wheel, screw driver

17
Simple Machines
18
Eduardo is helping his family move out of their
old house. Help him decide which task would be
easier, and then help him figure out what simple
machine makes the job easier.
19
Eduardo has to move some heavy boxes into the
moving truck.
A
B
B would be easier because a ramp is an inclined
plane.
20
Eduardo has to move a heavy box a long distance.
A
B
A would be easier because the wagon has wheels
and axels.
21
Eduardo needs to tear off a piece of packing tape.
A
B
B would be easier because the edges of the
scissors are wedges.
22
Eduardo needs to move a heavy box to his room on
the fourth floor.
A
B
B would be easier because Eduardo is using a
pulley.
23
Eduardo needs to help his father move the
refrigerator.
A
B
A would be easier because the dolly is a lever
(with wheels and an axel).
24
Eduardo needs to help his father change a flat
tire on the moving truck.
A
B
B would be easier because a jack uses a screw.
25
Now that Eduardo and his family have reached
their new house, they need some help in unpacking
their belongings. Help Eduardo decide on the
best simple machine to use in each situation.
26
Eduardo needs to open the boxes his mom sealed
with packing tape. What simple machine should he
use?
Eduardo should use a wedge (probably a pair of
scissors).
27
The door to the moving truck is jammed shut.
What simple machine might Eduardos father use to
open it?
Eduardos father should use a lever (most likely
a crowbar).
28
Eduardo needs to carry the boxes out of the
moving truck. What simple machine will make this
easier?
Eduardo needs an inclined plane (a ramp) to carry
the boxes out of the truck.
29
There is a flagpole outside Eduardos new school.
What simple machine could be used to raise and
lower the flag?
A pulley is used to raise and lower the flag.
30
Eduardos mom wants to hang a cabinet in the new
kitchen. What simple machine might she use to
attach it to the wall?
Eduardos mom could use a screw to attach the
cabinet to the wall and hold it in place.
31
Eduardo helped his father install doorknobs in
the new house. What kind of simple machine is a
doorknob?
A doorknob is a wheel and axel.
32
Simple Machines
Lever
Wedge
Inclined plane
Wheel and axel
Screw
Pulley
33
Identifying Simple Machines
Inclined plane / Lever
Wheel and axel
Wedge
Screw
Pulley
Inclined plane
34
Image Sources

• lthttp//etc.usf.edu/clipartgt
• lthttp//www.oz.net/peragine/doorknob.jpggt
• lthttp//www.theteachersguide.com/clipart/scissors.
  gifgt
• lthttp//www.weprintcolor.com/stockimages/construct
  ion/images/Black20metal20crowbar.jpggt
• lthttp//67.19.222.106/military/graphics/flagpole.j
  pggt
• lthttp//www.morris.umn.edu/UMMimages/public/images
  /campus_misc/flagpole.jpggt
• lthttp//www.phillips-screw.com/images/homeMain.jpg
  gt
• lthttp//mws.mcallen.isd.tenet.edu/mchi/ipc/ch15htm
  /images15/Screw.jpggt
• lthttp//www.discountramps.com/handi-van_ramp.gifgt
• http//staff.harrisonburg.k12.va.us/mwampole/1-re
  sources/simple-machines/flag-pole.jpg

35
Images Sources (cont.)

• lthttp//www.physics.uwaterloo.ca/demo/bikewheelgyr
  o.htmlgt
• lthttp//www.piratescave.co.uk/about_us.htmgt
• lthttp//staff.harrisonburg.k12.va.us/mwampole/1-r
  esources/simple-machines/handicap-ramp.htmlgt
• lthttp//library.thinkquest.org/J002079F/wedge.htmgt
  
• lthttp//www.idahoptv.org/dialogue4kids/season7/sim
  plemachines/facts.htmlgt
• lthttp//www.scienceclarified.com/Io-Ma/Machines-Si
  mple.htmlgt