Which of the following is heat absorbed by a substance melting from a solid to a liquid

A substance absorbs heat during two major changes in its state which are melting and boiling

When a solid substance absorbs enough heat, it starts to liquefy due to the intense energy of the constituent atoms and molecules. Example melting of ice.

When a liquid absorbs heat, it starts to vaporize and escape into the atmosphere.

Explanation:

During the change of solid to liquid called melting or fusion and during change of liquid to gas called as vaporization or boiling the heat is absorbed to overcome the force of attraction between molecules of that specific component called as hidden heat that is LATENT heat may be latent heat of fusion or vaporization

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.