WHY DOES SAND HEAT FASTER THAN WATER?
The heat capacity of a substance depends on the number of ways that heat energy can be taken up at the particle level- vibrational, translational etc other than simple movement of the molecules( Kinetic energy). The particles( Si, O, Na etc) must have less ways to distribute the radiant energy of the sun and thus it takes less Joules of energy to raise the temperature( a measure of the average kinetic energy) of the sand than it does the temperature of water. Hence when subjected to the same radiant energy, the sand gets hotter than the water. Metals get even hotter.
