4. Compare LPG and wood as fuels.
5. Give reasons.
(a) Water is not used to control fires involving electrical equipment.
(b) LPG is a better domestic fuel than wood.
(c) Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.
Answer (2)
LPG is a cleaner and more efficient fuel than wood, which can produce harmful emissions when burned. Water should not be used to extinguish electrical fires due to the risk of electric shock, and aluminum pipe prevents paper from catching fire by dissipating heat. Understanding these concepts highlights the importance of safety in fire management and the choice of fuels.
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Comparison of LPG and wood as fuels:
Efficiency: LPG (Liquefied Petroleum Gas) is a more efficient fuel than wood. This means that LPG provides more energy output per unit of weight compared to wood.
Environmental Impact: LPG burns more cleanly than wood. Burning wood releases more smoke and pollutants, which can contribute to air pollution and respiratory problems.
Convenience: LPG is easier to store and handle as it is supplied in cylinders with controlled supply. Wood, on the other hand, requires more space for storage and needs chopping or purchasing in a suitable form for burning.
Consistency: The energy content of LPG is consistent, whereas wood can vary greatly in its moisture content and thus its energy efficiency.
Reasons:
(a) Water is not used to control fires involving electrical equipment because water is a good conductor of electricity. If water is used, it can conduct electricity and pose a risk of electric shock to anyone trying to extinguish the fire.
(b) LPG is a better domestic fuel than wood due to its higher calorific value, cleaner combustion, and ease of use and storage. LPG provides more energy and produces fewer pollutants compared to wood.
(c) Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not. This is due to the aluminum pipe conducting heat away from the paper rapidly. Paper alone heats up quickly and reaches its ignition temperature; however, when in contact with the aluminum, heat is conducted away, preventing the paper from reaching its ignition temperature easily.
