• 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. Communication: the Key To Designing Safely.

    One proposed solution is through education, certainly of those who are currently in training but also those in professional practice through continual professional development and their professional bodies. This however is of limited use as we have previously acknowledged that construction is constantly developing techniques and materials and availing ourselves with all that happens in construction through CPD is unrealistic.

  2. TENSILE TESTING OF METALS

    The linear region is quite long and the slope is steep which indicates that the Young modulus is high; this is expected from a material such as steel because of its ductile properties. When the steel passers the linear region it deforms permanently.

  1. The aim of this experiment is to investigate the affects on the rate of ...

    When first exploring this experiment I felt that the silver backed card would be the best insulator, but because of the evidence I have deduced I predict that the bubble wrap and polystryrene will be the better insulators. From my results I can deduce that the rate of heat loss decreases is decreased dramatically by all insulating materials.

  2. Find out which is the most effective insulating material out of a range of ...

    the bubble wrap had held onto more heat compared to the foam. The first set of results tell me that the double glazing theory works. The second set of results prove the first set of result are true and reinforce the double glazing theory.

  1. EFFECT OF MOISTURE ON THE MECHANICAL PROPERTIES OF NYLON

    For example; Nylon-6, -66 & -610 but not Nylon-612,-11 & -12 are soluble in 90% formic acid at room temperature. Crystallinity and morphology are also effect solubility. A 4.2 molar solution of HCL acid at room temperature rapidly dissolves Nylon-6 and low melting terpolymers but has no effect on Nylon -66, -610, -11, and -612.

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

    Figure 1 Figure 2 Effect of heat on concrete after 2 hours of exposure to 1000?C Fire (1) Fibre reinforced concrete and (2) Ordinary reinforced concrete (Takenaka Co, 2000) Clay bricks Brickwork is normally a very good fire-resisting material.

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

    Similarly in the crosshead, the top surfaces of the steel axle in contact with the bearing pads were fretted and scored.

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

    Their earliest tool was using fire to mould wood, but they abandoned this because it was unpredictable and unreliable. Our building projects are community events, even a source of revenue in our economy. Some people are very attached to the idea that only slaves construct the pyramids.

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