Form 4 Physics Ques

1. Total internal kinetic energy of a object is the total sum of kinetic energy of the molecules in the object.

Obviously, a larger object has more molecules than a smaller object. But logically, the two objects can be at the same temperature. If they have the same total internal kinetic energy, then the average internal kinetic energy of the molecules in the larger object should be smaller than that of the smaller object. And this leads to contradiction.

So, it should be if the two objects have the same AVERAGE INTERNAL KINETIC ENERGY must have the same temperature. As temperature is a measure of average kinetic energy of the molecules. So, this statement is false.



2. At the changing state of the object. For example, solid melts to liquid, liquid vaporize to gas. Energy from heating is supplied to increase the potential energy of the molecules, not increasing average kinetic energy (temperature). The energy is supplied for the latent heat of the substance.

This circumstance persists until all of the molecules have change the state. Then energy from heating will be supplied to raise the temperature of the substance.