Question

If a substance is hot, its particle will move:
a) more faster than cooler object
b) more slower than the cooling object
c) at the same rate as the cooler object
d) none of the above

Answer 1

Hint: The substance basically turns hot because the individual particles of the substance gain the energy. Let us assume that the particles of the substance are free to move about in the given space. Hence these particles in motion possess greater kinetic energy than the particles of the same substance at cooler state. Therefore from this information we can conclude what will be the situation from the options provided.

Complete step-by-step answer:
The particles of the substance are free to move about in space. When the temperature of the substance is increased it appears that the substance has turned hot. This is because the particles of the substance gain heat energy and move randomly as they possess very high kinetic energy. Let us say the kinetic energy of a particle of the substance initially was,
$K.{{E}_{INITIAL}}=\dfrac{1}{2}m{{v}^{2}}J$ , where m is the mass of the particle and v is the initial velocity of the particle. After heating let us say the kinetic energy of the particle increases to $K.{{E}_{FINAL}}=\dfrac{1}{2}m{{V}^{2}}J$where V is the final velocity of the particle. The mass of the particle does not change when it's heated. Which implies the initial velocity of the particle increases. Since the final velocity of the particle is greater, we can conclude that the particles of the hot substance will move more faster than that of the cooler substance.

So, the correct answer is “Option A”.

Note: It is to be noted that in solids the particles of the substance do not move about their mean position. But they absorb energy i.e. if the substance turns hot, then the particles will vibrate along their mean position with greater amplitude. In liquids and gases the particles are free to move about in the given space.