Explain why:
i) It is very difficult to burn a heap of fresh green leaves, but it catches fire easily once leaves dry up.
ii) A lighted match can ignite a splinter of wood but not a log of wood.
iii) A blanket is wrapped around a person if his clothes have caught fire.
Explain why:
i) It is very difficult to burn a heap of fresh green leaves, but it catches fire easily once leaves dry up.
ii) A lighted match can ignite a splinter of wood but not a log of wood.
iii) A blanket is wrapped around a person if his clothes have caught fire.
i) Fresh green leaves have water content in them which raises the ignition temperature. But dried-up leaves have low ignition temperature and catch fire easily.
ii) A lighted match produces enough heat to reach the ignition temperature of the splinter so it catches fire. Whereas heat produced by a lighted match is not sufficient to reach the ignition temperature of a log of wood which is quite high and log of wood does not catch fire.
iii) A blanket is wrapped around a person if his clothes have caught fire to cut the supply of air (oxygen) supporter of combustion. This helps in extinguishing the fire (put out the fire).
i) Fresh green leaves have water content in them which raises the ignition temperature. But dried-up leaves have low ignition temperature and catch fire easily.
ii) A lighted match produces enough heat to reach the ignition temperature of the splinter so it catches fire. Whereas heat produced by a lighted match is not sufficient to reach the ignition temperature of a log of wood which is quite high and log of wood does not catch fire.
iii) A blanket is wrapped around a person if his clothes have caught fire to cut the supply of air (oxygen) supporter of combustion. This helps in extinguishing the fire (put out the fire).
