The expression latent heat refers to the amount of energy released or absorbed by a chemical substance during a change of state that occurs without changing its temperature, meaning a phase transition such as the melting of ice or the boiling of water.
I don’t know about Latent Heat of Ashes...
a) The friction force only acts in the opposite direction to a horizontal force on an object. The only forces acting on the block described are gravity and the normal force from the table, both of which are in the vertical direction. Therefore, there is no friction force acting on the block...
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One of my friend has completed his phd in biotechnology at the age of 32 , i know its very late to finish but he told me that the results were very slow to achieve.