Molecular Kinetic Energy Formula

Molecular Kinetic Energy Formula

The kinetic energy associated to a system that in obeys the Maxwell-Boltzmann distribution. It is an average energy.

Average kinetic energy = 3 / 2 (Boltzmann constant) * Temperature

The equation is:

<k>= 3/2 k T

Where:

<K>: Average molecular kinetic energy

k: Boltzmann constant. (1.38*10(-23) m2 kg /(s K2))

T: Absolute Temperature in Kelvin.

Molecular Kinetic Energy Formula Questions:

1) If the temperature of a bunch of particles in a closed box is 500 K, what is the kinetic energy of those particles?

Answer:

The kinetic energy is found with the formula:

<k≥ 3/2 kT

then,

<K> = 3/2 (1.38*10(-23) J /K *500 K)

<K> = 1.035 *10(-20) J

2) The same box before, but at temperature of 5000000 K, what is the value of the kinetic energy, larger or shorter?

Answer:

The kinetic energy is found with the formula:

<K≥ 3/2 kT

then,

<K> = 3/2 (1.38*10(-23) J /K *5000000 K)

<K> = 1.035 *10(-16) J

As temperature rises, the kinetic energy is larger.

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