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

Construction resources.

Extracts from this document...


        Construction resources make use of physics in many of their products. Two that I have picked are solar collectors and their use of insutation.

        Insulators have the purpose of preventing conduction, convection and radiation to unwanted areas. There are a wide range of techniques and materials used in doing this and I am going to look in depth at this idea.

The company uses solar collectors in many different ways, their main purpose is to collect solar energy and heat energy. They can be used to heat and power many different appliances.

Photovoltaic cells:

Photovoltaic cells transfer the energy carried by the electromagnetic waves that make up sunlight directly to an electrical circuit in order to make a current flow.Light excites electrons to move from one layer to another through semi conductive silicon materials. Only a fraction of a volt is produced so a large array is needed to produce appreciable currents, usually about 20W to 100W. The Photovoltaic cells produce DC current so if alternate current AC is desired then an inverter is required. AC form is commonly available from the mains.


Solar cells:

        Sunlight may also be used to heat water directly.

...read more.



Conduction, where heat energy is transferred through solid materials, metals are normally the best conductors. There are a number of factors that affect thermal conductivity. Increasing the area of the cross-section of the solid through which hear flows increases the rate of flow, however increasing the thickness of the wall decreases the flow of heat. Provided that a steady state has been reached (where the temperature of any point is not changing through time) then the rate of flow of heat ΔQ/Δt is given by:

ΔQ/Δt --> A ΔT/Δx

Besides the physical dimensions of the materials, another factor affecting rate of flow is the properties of the material, the Thermal Conductivity of the materials λ through which the heat energy is travelling is the constant of proportionality in this relationship, so:

ΔQ/Δt = -λA ΔT/Δx

The units for thermal conductivity are watts per metre per kelvin.

The Quantity ΔQ/Δt is called the temperature gradient.

On my visit to Construction resources I noticed that they have used these Physical conclusions in there insulation. One in particular is ‘Homatherm’ a wall and roof insulator. The slabs are thick which means less flow of heat, and have a thermal conductivity is only 0.

...read more.



Microsoft Encarta

Heinemann Advanced Science

Salter’s Horner’s AS Advanced Physics

Strengths and Limitations of Photovoltaic cells:

Since one photovoltaic cell only produces a small fraction of a volt, large arrays are required to produce appreciable voltages. This requires a lot of space and the cells need to be in a place where no shadows will be cast on them. This limits what they can be used for. Also the amount of power produced by the photovoltaic cells directly depends on the amount of sunlight, so they cannot be relied on to produce power for something that constantly needs it. The only way this can be overcome is if some power was stored for a rainy day. But this again would take up space. Also an array of solar collector will be expensive and have a long ‘pay back’ time. However it is environmentally friendly and after the pay back time, savings can be made. Also photovoltaic cells can be made look attractive depending on where they are placed.

Strengths and Limitations of solar cells:

 The solar cells have similar limitations to the photovoltaic cells in regards to positioning and cost but a small array is only required to produce enough hot water for something like residential showers or central heating. This is economical and environmentally friendly and solar cells are quite versatile.


...read more.

This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism 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 Electricity and Magnetism essays

  1. Finding a material's specific heat capacity

    This is because specific heat capacities of copper and water vary slightly according to temperature, as does the rate of heat loss. In addition, at higher temperatures the resistance of the circuit will increase and the water could evaporate. * Insulation - for the repeat of the experiment, the same

  2. How Does Insulation Affect the Rate of Cooling?

    This would be used to contain water, 100ml it is metal so it is a good conductor of heat. The cotton wool would be wrapped around it. -Kettle. This would be used to boil water, 100�c. -Glass beaker. This would be used to measure the volume of water -Thermometer.

  1. A Visit to Ashford Hospital

    An electron may lose any fraction of its energy in this process. The most energetic X-rays (ie. Those whose wavelength is ?min). X-rays with longer wavelengths are the result of electrons losing less than their total energy. The line spectrum is the result of electron transitions within the atoms of the target material.

  2. Investigation on Photovoltaic Cells

    Along with the benefits come disadvantages; a drawback of PV cells is that they are expensive to install but once installed no other costs are needed. Furthermore, solar electricity is not available at night unless a storage power system is in place which is also expensive.

  1. Energy Resources.

    And this all occurs without any damage to our environment. Another way the sun can be used is to heat water. This simple and efficient way of using the sun is called solar thermal technology. It can and is used to heat water for schools and homes and produce electricity for power companies.

  2. Super Conductivity

    be seen , such a "magnetic" field would have no south or north pole . At the same time external electromagnetic waves would not be able to penetrate into the conductor since there is no electromagnetic field present with which to interact.

  1. Investigating The Heat Of Combustion Of Alcohols.

    Fair Test: To make sure that this experiment is as accurate as possible we must keep all factors constant except the KEY VARIABLE which in this case is the alcohol burnt to heat the water. As I have mentioned earlier there are a variety of different variables that can be changed.

  2. Photovoltaic Cells.

    The only problem being is that PV Cells are very expensive and it is one of the most expensive ways of generating electricity. An individual photovoltaic cell will typically produce between 1 and 2 watts. This is not a lot so to increase the power output; several cells are interconnected to form a module.

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