Is fire extinguished more effectively by hot water or cold water ?

Q: Is fire extinguished more effectively by hot water or cold water ?

Sol: Fire is extinguished by the vaporation of water which lowers the temperature of the burning body . Further the water vapour envelops the body , keeping oxygen away . Hot water evaporates more than cold water as it is closer to its boiling point , that is hot water is more volatile than cold water . The latent heat of evaporation being large , hot water will extinguish a fire more effectively than cold water .

Why does a weighted metallic wire and not a nylon wire cut through ice ?

Q: Why does a weighted metallic wire and not a nylon wire cut through ice ?

Sol: Due to pressure , the melting point of the ice below the wire is lowered . Heat is conducted through the metallic wire from above to melt the ice below the wire . The wire passes through the water formed which is reconverted to ice after being relieved of the pressure . This is possible only when the wire is a good conductor of heat . Nylon is a bad conductor .