Which ball has lower heat energy ? A metal ball of 10kg at 100 degrees or a ball of 75 kg at 25 degrees.

The heat energy depends upon the amount of molecules of body so the heat energy is less in ball of mass 10 kg in comparison to ball of mass 75 kg. 

The convective heat transfer coefficient (h), defines, in part, the heat transfer due to convection. The convective heat transfer coefficient is sometimes referred to as a film coefficient and represents the thermal resistance of a relatively stagnant layer of fluid between a heat transfer surface and the fluid medium.Most of the preheating of fuels ahead of a fire is by radiation of heat from the fire. As the fire front gets closer, the amount of radiant heat received is increased. Convection is the transfer of heat by the physical movement of hot masses of air. As air is heated, it expands (as do all objects).

Cooking with radiant heat is a more physical process. ... These elements radiate their heat without appreciably warming the surrounding air. Then the heat is sent out in waves through the ceramic cover to the cookware. This is the traditional process for heating and cooking food that most of us are accustomed to.A common example of conduction is the process of heating a pan on a stove. The heat from the burner transfers directly to the surface of the pan.

Molecules will move more quickly at higher temperatures, and therefore heat will be transferred through the material at a higher rate. This means that the thermal conductivity of the same sample has the potential to change drastically as the temperature increases or decreases.Heat transfer coefficient depends on both the thermal properties of a medium, the hydrodynamic characteristics of its flow, and the hydrodynamic and thermal boundary conditions. ... The dependence of the Nu and St numbers on the Re and Pr numbers plays an essential role in heat transfer by forced convection.