• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Conduction and materials

Extracts from this document...

Introduction

Chris mullet Conduction-: There are lots of different types of conduction. The main theory behind conduction is where vibrating molecules come into contact with adjoining molecules and set them vibrating faster and hence they become hotter; this process is carried on throughout the substance without appreciable displacement of the particles. This is commonly known as Conduction. There is also Thermal Conductivity. This is as follows; because some materials allow heat to pass through them quite quickly. Most non-metals allow heat to pass through them slowly. Materials that allow heat to pass through more slowly are called poor Conductors of heat or Insulators. Stripping knives, soldering irons, cooker or oven doors are made of metal and, when heated, quickly become too hot to be held or touched. ...read more.

Middle

Heat travels through all materials but some will allow it to travel through quickly while through others it may be very slow. This heat movement is known as COONDUCTION. Materials, which allow fast movement of heat, are known as good Conductors. When the movement is slow they are called Poor Conductors. Copper is a very good conductor of heat and is called a material of high TTHERMAL CONDUCTIVITY (Thermal means heat). In comparison, still air is a poor conductor of heat so has a low thermal conductivity. The amount of heat, (Q), transmitted between the surfaces of a slab of material of uniform thickness and composition varies: (a) Directly with the area (A) (b) Directly with the temperature difference between the faces ((2-(1) (c) Directly with the time of flow (T) ...read more.

Conclusion

Typical values of 'k' for different materials when dry are given in figure that ive produced (thermal conductivity increases with moisture content). Find how much heat is conducted per second through 1m2 of sheet glass, 5mm thick, when the temperature difference between the faces is 10 deg C. (k=1.05W/m deg C) Materials Thermal Conductivity k W/m deg C Resistivity r (=1/k) Asphalt 1.2 0.9 Asbestos Cement 0.3 3.5 Brickwork (in commons) 1.3 3.5 Dense Concrete 1.4 0.7 Clinker Concrete 0.4 2.8 Sandstone 1.3 0.8 Granite 2.7 0.4 Plaster 0.6 1.8 Wood 0.1 7.7 Glass 1.1 1.0 Plaster Board 0.2 6.3 Slag wool 0.1 20.0 Cork Board 0.1 20.0 Fiber Glass 0.0 25.0 Expanded Polystyrene 0.0 3.3 Table of thermal Conductivity and Resistivity (Typical Values for dry Materials) Q=kAT((2-(1) D =1.05x1x1x10 =2100J 0.005 This is a rate of heat loss of 2100W (2100J/s) per square meter. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Resistant Materials section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Resistant Materials essays

  1. In this investigation I aim to find out which materials are the best insulators. ...

    These things would have kept my experiment much fairer. Another factor which could have effected my results was that I did not seal the copper beakers with lids.

  2. TENSILE TESTING OF METALS

    Several applications which this material is used for are cans, corvettes and spaceships, which proves how diverse this material can be. Aluminium alloys form vital components of aircraft and rockets as a result of their high strength to weight ratio.

  1. The Effect of Different Types of Insulation on Heat Retention

    As the heat energy is slowed down, so is the rate of heat retention because the energy through the particles is moving very slowly. When compared to the control, bubble wrap is a better insulator because of the trapping of heat energy inside the air pockets, so the water stays

  2. EFFECT OF MOISTURE ON THE MECHANICAL PROPERTIES OF NYLON

    NYLON 66,69,610,& 612 The Nylon 66 salt is prepared by reacting the hexamethylenediamine and adipic acid in boiling methanol, the comparatively in soluble salt (melting point 190-191*C) precipitating out. A 60% aqueous solution of the salt is then run in to a stainless steel autoclave together with a trace of acetic acid to limit the molecular weight (9000-15000).

  1. Discuss about the ways how the number of injuries and deaths can be reduced ...

    Apart from being a flexible partition, it is also a very good material to resist fire. Pure gypsum consists of calcium sulphate and water of crystallisation. Other materials such as glass fibre and vermiculite also exist but in small quantities.

  2. This case history documents events that occurred at the Markham coal colliery in Derbyshire, ...

    Indeed, the investigators observed rubbing marks on the brake rod where it passed through the trunnion, Contact between rod and trunnion would be associated with a frictional force which would prevent some of the axial load from being transmitted to the lower end of the rod.

  1. A comparison between the Egyptian architecture, with that of the Olmecs, an early civilization ...

    Hence, the entire process was quite communal, involving and uniting people from all facets of the social hierarchy. Modern Egyptologists such as Mark Lehner believe that it required 20,000 men to build a pyramid. Our constructions involve better techniques and organization than the Olmecs.

  2. Communication: the Key To Designing Safely.

    Whilst fines should avoid the risk of causing bankruptcy there may be cases where an offence is so serious that the defendant ought not to be in business. Table 1: Average fines imposed per industrial sector (HSE, 1998) Sector Construction Manufacturing Service Year 1993/94 1997/98 1993/94 1997/98 1993/94 1997/98 Average Fine �3384 �3173 �2973 �5895 �3939 �5726 No.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work