IB Design Technology Topic A3.1.4 Physical Properties of Materials Revision Notes (SL/HL)

IB Design Technology Topic A3.1.4 Physical Properties of Materials Revision Notes (SL/HL) | RevisionDojo

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Physical Properties: What You Can Measure Without Destroying the Sample

A3.1.1 defined the physical family, so this lesson goes straight to the six properties inside it.
What they share is that they are intrinsic: they stay the same no matter how big or what shape the sample is, so they can be found by non-destructive testing.
That is why a supplier can print them on a datasheet: the number holds for every piece of that material you will ever buy.

Density: How Much Mass Is Packed Into a Volume

Definition

Density

The mass per unit volume of a material (usually measured in kg/m³ or g/cm³). Its a measure of mass divided by volume (ρ = m/V)

Weight: high-density materials such as steel suit structures that need strength, while low-density aluminium is preferred in aerospace to cut weight.
Buoyancy: density decides whether an object floats or sinks in a fluid.
Density is the property most often traded against strength, because the lightest option is rarely the strongest one.

Example

Aluminium's low density makes it an ideal material for aircraft.
Every kilogram saved is fuel not burned across the aircraft's whole working life.

Thermal Conductivity: How Fast Heat Travels Through

Definition

Thermal Conductivity

A measure of how quickly heat passes through a material when there is a temperature difference across it. It is measured in watts per metre per degree Celsius (W/m·°C).

A material with high thermal conductivity moves heat quickly, and one with low thermal conductivity holds it back.
Metals sit at the conducting end of the scale, while polymers, ceramics and trapped air sit at the insulating end.

Analogy

Think of thermal conductivity as a road for heat.
A high-conductivity material is a wide, fast motorway, so heat travels through quickly.
A low-conductivity material is a narrow, slow lane that restricts the flow.

Where It Matters in Products

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Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

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Lorem ipsum dolor sit amet, consectetur adipiscing elit.
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Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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Physical Properties: What You Can Measure Without Destroying the Sample

A3.1.1 defined the physical family, so this lesson goes straight to the six properties inside it.
What they share is that they are intrinsic: they stay the same no matter how big or what shape the sample is, so they can be found by non-destructive testing.
That is why a supplier can print them on a datasheet: the number holds for every piece of that material you will ever buy.

Density: How Much Mass Is Packed Into a Volume

Definition

Density

The mass per unit volume of a material (usually measured in kg/m³ or g/cm³). Its a measure of mass divided by volume (ρ = m/V)

Weight: high-density materials such as steel suit structures that need strength, while low-density aluminium is preferred in aerospace to cut weight.
Buoyancy: density decides whether an object floats or sinks in a fluid.
Density is the property most often traded against strength, because the lightest option is rarely the strongest one.

Example

Aluminium's low density makes it an ideal material for aircraft.
Every kilogram saved is fuel not burned across the aircraft's whole working life.

Thermal Conductivity: How Fast Heat Travels Through

Definition

Thermal Conductivity

A measure of how quickly heat passes through a material when there is a temperature difference across it. It is measured in watts per metre per degree Celsius (W/m·°C).

A material with high thermal conductivity moves heat quickly, and one with low thermal conductivity holds it back.
Metals sit at the conducting end of the scale, while polymers, ceramics and trapped air sit at the insulating end.

Analogy

Think of thermal conductivity as a road for heat.
A high-conductivity material is a wide, fast motorway, so heat travels through quickly.
A low-conductivity material is a narrow, slow lane that restricts the flow.

Where It Matters in Products

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

A. Design in theory8 subtopics

B. Design in practice8 subtopics

C. Design in context8 subtopics

IB Design Technology Topic A3.1.4: Physical Properties of Materials Notes

A. Design in theory8 subtopics

B. Design in practice8 subtopics

C. Design in context8 subtopics

Physical Properties: What You Can Measure Without Destroying the Sample

Density: How Much Mass Is Packed Into a Volume

Thermal Conductivity: How Fast Heat Travels Through

Where It Matters in Products

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Physical Properties: What You Can Measure Without Destroying the Sample

Density: How Much Mass Is Packed Into a Volume

Thermal Conductivity: How Fast Heat Travels Through

Where It Matters in Products

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account