Water is falling from height of 84 m. If half of the energy of water is converted into heat, the increase in the temperature of the water at the bottom is:Required to answer. Single choice. 411.6 deg. C
823.2 deg. C
0.098 deg. C
0196 deg. C

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other