A WORLD OF MACHINES

thunderclingAI and Robotics

Nov 13, 2013 (4 years and 1 month ago)

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A WORLD OF
MACHINES

Woodleigh School


Student work book




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Experiment 1:
Household machines

We know that machines are devices that assist us in making tasks easier,

and that many of these are
very simple in nature.


Aim

To investigate

a range of simple household machines and try to discover how they work.


Materials

Your teacher will organise a group of simple household machines and place these in

positions
around the room. These could include a hand
-
drill, a zipper, an old clock,

penc
il sharpener, a knife
(and apple), old doorknob, chopsticks, tweezers, pliers, pair of

scissors, bottle opener, fi
shing rod,
corkscrew or whatever else is available.


Method

Draw up a table like the one below in your book and spend time carefully examining

each device
before completing your result
s. Use a bit of guesswork to fi
ll in the last

column of the table.


Results

Name of
Machine

Function of
Machine

How else
could we do
this job

How I think it
works

Diagram

What type of
simple
machine is
this?













































Discussion

1.


Which of these machines do you think is the most useful?


___________________________________________________________________________


___________________________________________________________________________


2.


Which machine did you find the most diffi
cult to discover how it works? Explain.


___________________________________________________________________________


___________________
________________________________________________________




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Science in action: Leonardo da Vinci


the Machine Man


Leonardo da Vinci was born in Vinci, Italy, in 1452. He was

a brilliant artist

the Mona Lisa and the
Last Supper are

two of his works. His s
tanding as a technological giant did

not become widely known
until centuries after his death

in 1519. Many of his fantastic creations were recorded

in back
-
to
-
front
mirror writing in his notebooks because

he tried to disguise his ideas from others.


Leona
rdo embarked on a quest for knowledge in a wide range of areas,

including geology, optics,
acoustics, music, botany, hydraulics, anatomy

and naval armaments. He was said to be handsome,
generous and

charming, but also unreliable and vain. He dressed in bri
ght, striking

clothing while
other men wore long, dark
-
coloured robes.


His designs for inventions included a crane for emptying ditches, a

therapeutic armchair, folding
furniture, a type of armoured tank, a

bicycle, spinning and weaving machines, various

weapons, and
even a

robot with limbs that could be moved by a series of cables and pulleys.

He designed a range
o
f wonderful but unsuccessful fl
ying machines.

Some resembled large butterfl
ies with four wings
and included pedals,

stirrups, harnesses, steer
ing cables and standing platforms. One of his

designs
could take off vertically and was powered by a rotating blade

it

was perhaps the fi
rst helicopter
ever imagined. The designs he imagined

were ahead of his time and are evidence of a great genius.


Chall
enge

Working in a group, conduct some research into the

fascinating inventions of Leonardo da Vinci.
Write a

short script about a particular invention, or concentrate

on events in a specifi
c time frame
from his life. Discuss

the nature of the roles that ea
ch person in your group

will take in preparing for
and performing in a short

presentation for your class. After the presentation, hand

an evaluation
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sheet to your classmates in which they

can give you feedback on parts of this exercise that

were
completed
successfully, and then any constructive

criticisms that they can offer to help improve your
work

in the future. Write your own evaluation of the way your

group worked together to complete
this task.


1.

When and where was Leonardo born?


___________________________________________________________________________


___________________________________________________________________________


2.

What was he most famous for immediately after his death?


____________________________________________
_______________________________


___________________________________________________________________________


3.


What was unusual about the way he recorded his ideas in his

notebooks?


___________________________________________________________________________


___________________________________________________________________________


4.

Name three of Leonardo’s designs and comment on why they

are

seen to be before his time.


____________
_______________________________________________________________


___________________________________________________________________________


5.


Wh
y do you think the desire to fl
y has fascinated people for

so long?


___________________________________________________________________________


___________________________________________________________________________












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Experiment 2
: Levers

Aim

To investigate how a simple lever works.


Materials

• metre ruler (
ideally with holes every cm)

• slotted masses and hangers

• large paper clip

• stand and clamp


Method

1.


Hang the ruler through the paper clip positioned at the 50 cm mark as shown in Figure 5.21.
Hang a 100 g mass from the zero end of the ruler.


2.

What
mass do you think you will need at the other end to balance the ruler? Try this. Draw a
table such as the following one in your book and record this result.

3.


Now, take a 200 g mass, and hang it on the second side of the ruler in such a way that it
balances

the original 100 g mass. Where did you have to place it?

Record your results in the
table.

4.


Repeat this process with masses of 150, 250 and 300 g.


Results

Mass on right
-
hand side of ruler

Position of mass to balance 100g at 50cm from
pivot (fulcrum)

100



150



200



250



300



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Discussion

1.


Which class of lever is modelled in this experiment?


___________________________________________________________________________


___________________________________________________________________________


2.


As the pivot was moved further from the load, what happened to the effort required?


___________________________________________________________________________


___________________________________________________________________________


3.


Describe how th
is relates to a crowbar used as a lever. Where should the pivot be
positioned to make the job as easy as possible?


___________________________________________________________________________


_______________________________________________________________
____________

















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Science in Action: Nanotechnology


Small Wonders


Imagine walking to school with a computer

in your pocket that’s smaller than a marble.

Or imagine a
DVD that can hold 250 movies,

windows that can clean themselves, stain
-
resistant

fabrics, scratch
-
resistant paint and

notebooks filled with smart paper that you

can download text onto and change
whenever

you like.


It may sound like a fantasy, but these could all be possible

within the next 5 year
s, thanks to the
amazing new

fi
eld of

science called
nanotechnology
.

The idea of building th
ings directly with atoms
was fi
rst

suggested by the brilliant physicist Richard Feynman

in 1959, but it has only been in the
l
ast
decade that

we have been able to begin to develop this technol
ogy.


Nanotechnology is all about making machines from

individual molecules, so small that they are
measured in

nanometres. What is a nanometre? It is one
-
billionth of a

metre, or about 1/80 000 the
diameter of a human hair!

Microelectromechanical systems
(called MEMs) are tiny

devices etched
from silicon that have moving mechanical

parts and electronic parts. An acceleration sensor in a
MEM

triggers the airbags in cars.


A team in California has built a prototype of an extremely

small and sensitive nano
-
ea
r. One

day,
these will be injected into

the bloodstream of patients to

detect malfunctioning cells by

listening to
the noises that the

cells make. Nano
-
ears could be

sent to other planets to listen

for tiny oceanic
creatures.


Molecular micromachines

By b
orrowing clues from nature, scientists are now developing their

own molecular micromachines.
These machines can be built to

perform complex tasks. It is envisaged that in the not too distant

future, billions of such machines may be built like this, without

large manufacturing plants and at a
relatively

low cost. In fact, in the right environment, many

components will almost build themselves!


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Dr Vijoleta Braach Maksvytis of the CSIRO

Communications and Industrial Physics is

involved in a
project on artifi

cial photosynthesis.

Imagine if we could develop micromachines to

create a
c
hemical surface that will use the Sun’s

energy while reducing greenhouse gases and

producing a
source of food at the same time!


Figure 5.14
Nanobots will one day move through ou
r bloodstream and work on some repair jobs!


Nanotubes

material of the future

Carbon nanotubes are one example of a product

of nanotechnology. These are strong, narrow,

hollow cylinders of carbon atoms. Some

nanotubes conduct electricity, and will be used

in building
tiny circuits. Other uses include

producing super
-
sensitive sensors and better microscopes than ever

before. Some scientists even think that nanotubes could one day be

used to build an elevator from
the Earth into space!


1.

Defi
ne what
nanotechnology is.


___________________________________________________________________________


___________________________________________________________________________


3.

List three n
ew inventions that the fi
eld of nanotechnology could soon make a reali
ty.


___________________________________________________________________________


___________________________________________________________________________


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4.

Explain what an MEM is and what these may do in the future.


___________________________________________________________________________


___________________________________________________________________________


5.

Explain what a molecular nanomachine is and give an example of a future use of these.


_______________
____________________________________________________________


___________________________________________________________________________


6.

What are nanotubes? Why are scientists excited about these structures?


_____________________________________________
______________________________


___________________________________________________________________________


Experiment 3
:
The turn of a screw

When you drive a screw into a piece of wood, the effort

you apply is over a much larger distance
than the depth

to which you have to sink the screw into the wood, which

might be only 2 cm.


Aim

To compare the turn of a screw with the depth it is sunk.


Materials

• A4 piece of paper • a screw

• pencil • piece of cotton

• scissors


Method

1.

Cut the piece of paper
diagonally into two

halves. (You only need to use one of these.)

2.


Place a pencil along the vertical edge,

as shown in Figure 5.30.

Mark the top of your pencil
on this sheet

and rule a horizontal line across. Cut this

section from the paper.


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3.


Measure the
length of the longest side of the triangle,
T
.

4.


Measure the length of the pencil.

5.


Roll the paper around the pencil, as shown in Figure 5.31.


Note: If the pencil were a screw, then
T
would be the

distance you would have to turn to sink it a
distance

equa
l to the length of the pencil.


Discussion


1.


How far would you need to turn this screw to sink it the distance of the pencil?


___________________________________________________________________________


___________________________________________________________________________


2.


The distance between the thread of the screw is called the pitch. Measure the pitch on

your
screw and record this.


______________________________________________________________
_____________


___________________________________________________________________________


3.


Taking your triangular sheet of paper, make a cut across from the tip of the pencil to

another point
A
, as shown in Figure 5.32.


________________________________
___________________________________________


___________________________________________________________________________


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Wind the pencil up again. Measure the new

length of
T
and the new pitch. Repeat the
process for a second point
B
.


(a)

As the thread,
T
,

became shorter, describe

what happened to the pitch.


________________________________________________________________________



(b) Do you think screws with threads close together

or further apart would be the most
effective in

holding wood securely? Exp
lain your answer.


___________________________________________________________________________


___________________________________________________________________________


4.


(a) Study a screw. Measure the length of the

thread by winding a piece of cotton
around it

and then measuring its length.


___________________________________________________________________________


___________________________________________________________________________


(b) About how many times longer is this than the

length of the screw? What does this extra
l
ength provide?


___________________________________________________________________________


___________________________________________________________________________




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Challenge Experiment
:
Moving up

It is obv
iously easier to push heavy objects up a ramp than to lift them vertically. The

force we use to
push or pull these objects is measured in a unit called the newton (N).

This can be measured by using
a spring balance or
a force sensor
. Set up a ramp
in your
laboratory and fi
nd a trolley or

cart and
some string. Design an experiment to compare the difference between the

force required to pull the
tr
olley up vertically from the fl
oor to your bench, and that

needed to pull it up a ramp. Remember to
alter only on
e variable at a time to ensure

that you conduct a fair test. Study a range of ramp angles,
graph your results or use a

spread

sheet to do this for you. Analyse y
our results and present your
fi
ndings by writing

a report or using a multimedia format of your
choosing. Suggest an extension of
this

work that could be investigated further in this topic.


Experiment 4
:
Investigating pulleys: some heavy lifting

Weight is the force pulling an object downwards due to gravity and is

measured in newtons.


Aim

To
investigate how a pulley and combinations of pulleys can assist us in lifting objects.


Materials

• 2 single pulleys • slotted 50 g masses

• 2 double pulleys • spring balance or force sensor

• 3 pieces

of rope or cord: • metre ruler

a

2 m length and 2 short pieces • narrow beam of wood


Method

1.


Load up 500 g of the slotted masses.

Measure the weight of these using a spring

balance,
making sure that it is zeroed

before you use it. Repeat this process

for the 400, 300, 200 and
100 g mass
es.

Record this data in Table 5.2 in the ‘Load’

column.

2.


Position the beam of wood across two

benches or tables and place some books

on top of
each end to make them secure.


3.


Attach a single pulley to the centre of

the beam using a short piece of cord, as

shown in
Figure 5.38.

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4.


Feed the longer cord through the pulley

and tie one end to the 500 g mass and the

other to
a
spring balance.

5.


Pull gently on the spring balance and

record the minimum force you need to

apply to lift the
masses through a height of

20

cm. Record data in Table 5.2.

6.


Repeat the process completed in step 5 for

the 400, 300, 200 and 100 g masses and

record
all data.


7.


Untie the masses and use the other short

piece of cord to attach the 500 g masses

to a
second, single pulley. Feed the lon
ger

cord through both single pulleys and then

attach the
spring balance as shown in

Figure 5.39.

8.


Repeat steps 5 and 6 to fi
nd the minimum

effort needed to lift each of the masses by

20 cm
using this new pulley arrangement.

Record data in your table.


9.

Set

up your equipment once again, this time using two double pulleys as

shown in Figure
5.40. Rep
eat the process once more to fi
nd the minimum

effort needed to lift each of the
masses 20 cm and record your results.




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Results

Arrangement

No. of
Pulleys

Mass
lifted (g)

Load (N)

Minimum effort required to lift
load 20cm

Single Pulley

1

500





400





300





200





100



Two single Pulleys

2

500





400





300





200





100



Two double Pulleys


500





400





300





200





100




Discussion

1.


Plot three line graphs showing how the effort required varied with the load lifted for

each of
the one
-
, two
-

and four
-
pulley combinations. (Use Effort (N) for the vertical and

Load lifted
(N) for the horizontal axes.)


___________________________________________________________________________


___________________________________________________________________________


2.


Describe how the effort altered as the load to be lifted increased.


________________________________
___________________________________________


___________________________________________________________________________


3.


Compare the effort required to lift the 500 g mass using the one
-
, two
-

and four
-
pulley

systems.

(a)

What can you conclude from this?


__
_________________________________________________________________________


___________________________________________________________________________





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(b) In what way did you compensate for these differences when pulling on the cord for

each
system?


___________________________________________________________________________


___________________________________________________________________________


4.


If Bob has a mass of 50 kg and a weight of approximately 500 N, predict the effort

that
would be requ
ired to lift Bob 20 cm off the ground using:

(a)

a single pulley


___________________________________________________________________________


___________________________________________________________________________


(b)

two pulleys


___________________________
_____________________________________________


________________________________________________________________________


(c) four pulleys.


___________________________________________________________________________


___________________________________________________________________________



Science in Action: Robotics

The possibility of human
-
like machines wandering around,

doing the housework and waiting on us
has been a dream

of many. Robots as machine tools certa
inly

do exist. They can perform a wide
range of tasks and

assist us in countless ways in industry, but have no

intelligence of their own.


Telerobotic systems extend our own ability to carry out particular tasks.

Robot hands were initially
very simple
pincers. They were developed

in the 1940s to safely handle radioactive substances. They
can now be

multi
-
fi
ngered with a thumb for greater dexterity. Telerobotic systems

are used in the
space programs, in under
-
sea exploration and in servicing

electricity
transmission lines without
risking lives.

Robots can be mobile, using wheels, tracks or legs, with computers

controlling their
paths. They can be fitted with a number of sensors that

detect position, speed, temperature, sound
or even touch. Video cameras

c
an be used to capture images, which are analysed and compared to
spot

differences from images already stored in a computer, thus providing

robot vision. Robots are
used in the manufacturing industry, to perform

tasks such as packing, testing, gluing and pr
ecision
drilling. Some mobile

robots are used as guards, in commercial cleaning operations and in

hospital
care to transport supplies.

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Robots also have many

applications in the medical fi
eld. Miniature

forceps worked by remote
control can be used to perf
orm delicate

brain surgery, as their movements are very precise
.
Robotic

systems

are being used in the USA and Japan for heart surgery and gastric

bypasses. Melbourne’s
Epworth Hospital has adopted the technology

and is currently utilising the da Vinci sys
tem pictured
in Figure 5.42 for

prostate surgery. Because these procedures are less invasive, patients have

a faster
recovery rate and suffer fewer complications than with

conventional surgery. The da Vinci system
was originally designed

in the USA by scie
ntists hopeful of enabling surgeons to operate

on soldiers
and astronauts from long distances away!


Figure 5.42

Professor Anthony Costello,

pictured sitting on the left,

is operating on a patient at

Melbourne’s Epworth Hospital.

He watches a
three
-
dimensional

image on a console, as he guides

miniature robotic ‘hands’ that

perform the
delicate surgery.


At Monash University’s Intelligent Robotics Research Centre,

Professor Andy Russell is making robots
that use sensors similar

to our own. His
latest robot is called RAT (Reactive Autonomous

Test

bed).
This little robo
t can follow scent trails to fi
nd its

way around a maze. Its built
-
in scent detectors
measure

the weight of incoming scent molecules. A handy tool

possibly around your brother’s day
-
old socks! It also has

an ultrasonic sensor to stop it from crashing into objects,

and a set of whiskers
as touch sensors! It is possible that

robots like RAT could one day be used not only to sniff for

drugs,
but also to sniff for explosives, land mines
or humans

buried below rubble.




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1.


Give two examples of the use of telerobotic systems.


___________________________________________________________________________


___________________________________________________________________________


2.


What types of stimuli can particular robots detect? How could this

be useful?


___________________________________________________________________________


___________________________________________________________________________


3.


How does robot vision

work?


___________________________________________________________________________


___________________________________________________________________________


4.


Describe how robots can be used in medicine.


___________________________________________________________________________


___________________________________________________________________________



Experiment 5
:
Gearing up


Aim

To investigate how the gears on a bicycle operate.


Materials

• a multi
-
geared bicycle

• a broom handle or piece of timber

• chalk


Safety


Keep fi
ngers clear of moving spokes on the wheel at all times.


Method

1 Lift the rear of the bicycle off the ground. Slide a broom handle or beam of wood

underneath the
metal bar
connecting the seat to the back forks. Support this beam

using stools as shown in Figure
5.51.

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2.

Use t
he gear levers to select the fi
rst gear, so that the chain wheel is on the smallest

sprocket and the rear sprocket is on the largest. Use chalk to make a
mark on the rear

tyre.
Slowly turn the pedals one revolution and count how many revolutions the rear

wheel
makes in this time. Now, count the number of teeth on the front and rear sprockets

and
enter this data in a table as shown below.

3.


Repeat the above p
rocess for a range of about ten gears. Test each gear combination for

a
ten
-
speed bike, or every second gear for a 21
-
speed bike.


Analysis and Discussion


1.


Plot a graph, possibly using a spread

sheet, showing the number of turns of the rear

wheel
on the
vertical axis and the gear number on the horizontal axis.


___________________________________________________________________________


___________________________________________________________________________


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2.


Write down a general conclusion that you c
an draw from your graph.


___________________________________________________________________________


___________________________________________________________________________


3 (a)

What effect does the gear ratio have on the number of turns the rear
wheel makes?


___________________________________________________________________________


___________________________________________________________________________


(b)

When using which gear system do we need to pedal with the most force?


________________________________________________________________________



(c)

When using which gear system do we need to pedal faster to maintain our speed?



___________________________________________________________________________


___________________________________________________________________________


4 Suggest one situation in which:

(a)

the lowest gear would be suitable


___________________________________________________________________________


_________________________________
__________________________________________


(b)

the highest gear would be the best one to use.


________________________________________________________________________


________________________________________________________________________