Engineering STUDIES PRELIM REVISIO

Multiple Choice

Q1. List all the simple machines ( L, IP, S, W/A, P, G)

• Lever

• Incline plane

• Screws

• Wheel and Axle

• Pulleys

• Gear

1st order lever order (EFL) and used in…

• Effort, Fulcrum, Load

• Used in: See saws, retractor, plier

2nd order lever (order, and used in

• Effort, Load, Fulcrum

• Used in, Wheel barrow, brake pedal

3RD Order lever (order, used in…

• Load, effort, fulcrum

• Fishing rod

• effort always larger then load in 3rd order lever

Q2. PREFIXES

Tera and Giga (not that important)

TERA: 10¹²

GIGA: 10⁹

Mega (M)

10⁶

Kilo (k)

10³

milli (m)

10^-3

micro (µ)

10^-6

nano (n)

10^-9

pico (p)

10^-12

Q3. DRAWING SYMBOLS (ask miss 00)

What should be included in a materials list (Item numb, Item desc, Materia type, Numbe)

• Item number, item description, material type, number

Q4. VECTORS

Is force a vector

YES

Is time a vector

No

Is load a vector

Yes

Is force a vector

Yes

Is stress a vector

NO

List of vectors

force, displacement, load, weight

Q5 Coeffiecent of friction

MEW= FF/RN

Q6 . QUALITY OF METALS

Why are FCC metals more ductile

• MORE DENSE SLIP PLANES

KEY POINT ( THE LESS THE SLIP PLANES THE…

fewer slip systems → lower ductility

What is an Alloy

An alloy is a mixture of two or more materials, where at least one is a metal.

Metals can occur naturally or extracted from earth….c

earthsc crust

Q11.Ferrous vs Non ferrous

Ferrous metals + metals

• Have iron as a PRIMARY constituent

  Iron, cast iron, carbon steel

Non ferrous metals + metals *copp, bras, bron

May contain Iron, but not primary constituent

• copper, brass, bronze

Q7. Ohms Law

• V=IR

Q8. Manufacturing Processes

Casting + different types of casting

• Heating up material, then placing in a mould

• Investment casting

What method are polymers made… (injec

INJECTION MOULDING

Rolling

• Pass a metal through a roller to form a circular or square bar

• Hot rolling- Easier, less dimensionally accurate

• Cold Rolling- Harder- More dimensionally accurate

Extruding

Passed through a die at an elevated temperature

Aliminium alloy window frame

Forging

Proccess of shaping a metal with forceful blows usually by hammering or pressing (The metal is often heated first to make it easier to shape)

One of the biggest advantages of forging is that it improves the grain structure of the metal

Hot Forging

• Carried out above the recrystillisation temperature

• Easier and quicker, results in rough surface finish

• unstressed

Cold forging

• Highly stressed

• Grainflow paraell

Q9. RECYLCING CONCEPTS AND WASTE MANAGEMENT

BEST TO WORST RANK( less waste design, reuse, recycle, dump landfill

1. Less waste design

2. Reuse

3. Recycle'

4. Dump for landfill

Q10. Components of force

i understand

Q11. Ferrous and Non ferrous - ALREADY DONE REFER BACK

Q12. Different types of forces (concur, non conc, colin

• Concurrent: Pass through same point

• Non concurrent: interest various points

• Co-linear: act along on the same line

Pricniple of transimilbilty

A force acting on a rigid body can be moved anywhere along its line of action without changing the external effect of the force on the body.

Q13. Friction Calculaiton (refer to book)

Q14. Alloying materials (defintion)

• Elements that are added to a base metal (usually a metal like iron or aluminium) to change and improve its properties.

Alloying materials can create.2 types of solid solution

• Interstitial

• Substitutional

Substituional solid solution *atoms…

• MUST BE SIMILAR IN SIZE

Interstitial

Atoms must be much smaller

Q15 Heat Treatment (5)- ferrous metals

• Annealing

• Process Annealing

• Normalising

• Spherodising

• Tempering

Annealing

Steel is heated about 900 degrees and then cooled very slowly (usually in a furnace)

Process Anealing

• Lower-temperature heating around 550-650 degrees on mild steel]

Normalisng

• Steel heated up to 900 degrees to relieve stress, then cooled in air

Spherodising (occurs when. during a rehatin after being quen…

Occurs during a rehating after steel has been quenched in 650-700 degrees

HARD CEMENTITE BREAKS UP INTO ROUND PARTICLES RESULTING IN STEEL BEING SOFT, LESS BRITTLE, EASIER TO MACHINE

Tempering - MAIN TO INCREASE TOUG…

Reheating quenched steel to 200-600 degrees, then cooled to reduce brittleness and INCREASE TOUGHNESS

Q16. Carbon Compostion

• 0.2 PERCENT

• 0.83

• 1.2

0.2 PERCENT

• Hypo- Euctoid

• More ferrite, less pearlite

0.83

• Euctoid

• All pearlite

1.2

Cementite and peralite

Hyper- Euctoid

Q17 Material testing

LOOK BACK ON FLASHCARD 76, BRAKING SYSTEM

3 types of material testing (tens, compre, hardness)

• Tensile Test

• Compressive test

• Hardnesst test

Q18 GEAR RATIO CALCULATION

• Attempt in book and understand

Gear ratio formula

Van / Var

• DRIVING/ DRIVER

Driving gear=

driving

driven =

driver

Gear ratio example + solution

The important thing is: when two gears are on the same shaft, they have the same rpm.

Q19. Stress and Strain calculation

Stress formula

• Load/ Area

Strain

• Extension/ Shortening / Original length

Engineering stress vs True stress (DIFFERENCE)

ENGINEERING STRESS: Uses the original

TRUE STRESS: Uses the actual at that time

Q20. AS1100

What are the Orthogonal Projection reccommended

• 3RD Angle projection

Height of bolt

0.7 D

Height of Nut

0.8 D

M20 X 4 (DIAMTER AND PITCH)

• Diameter = 20

• Pitch = 4

Image

• 1.8 D LONGER SIDE

• 1.6 D SHORTER SIDE

G- PITCH/2

iMPORTANT QUESITON BOLT AND NUT

done previous slide