Astrophysics - GRE Subject Test: Physics

Stefan-Boltzmann's equation for a blackbody states:

, where is the energy emitted each second, is the Stefan-Boltzmann constant, and is the temperature of the blackbody. Therefore, if we triple the temperature, the energy will increase by a factor of

The kinetic theory of gas states:

. Whenever the velocity of the individual gas particles is larger than the escape speed of the planet,

, the gas particles will leak into space and deplete the atmosphere. The physical property that determines this is the mass of the planet.

This is an application of Wein's Law that states the following:

, where is the wavelength of maximum emission of the object (measured in ), and is the temperature in . Since the wavelength and the temperature are inversely proportional, if we double the temperature, we must cut the wavelength by the same proportion. Therefore, the temperature must be halved.

Stefan-Boltzmann's equation for a blackbody states:

, where is the energy emitted each second, is the Stefan-Boltzmann constant, and is the temperature of the blackbody. Therefore, if we triple the temperature, the energy will increase by a factor of

The kinetic theory of gas states:

. Whenever the velocity of the individual gas particles is larger than the escape speed of the planet,

, the gas particles will leak into space and deplete the atmosphere. The physical property that determines this is the mass of the planet.

This is an application of Wein's Law that states the following:

, where is the wavelength of maximum emission of the object (measured in ), and is the temperature in . Since the wavelength and the temperature are inversely proportional, if we double the temperature, we must cut the wavelength by the same proportion. Therefore, the temperature must be halved.

Stefan-Boltzmann's equation for a blackbody states:

, where is the energy emitted each second, is the Stefan-Boltzmann constant, and is the temperature of the blackbody. Therefore, if we triple the temperature, the energy will increase by a factor of

The kinetic theory of gas states:

. Whenever the velocity of the individual gas particles is larger than the escape speed of the planet,

, the gas particles will leak into space and deplete the atmosphere. The physical property that determines this is the mass of the planet.

This is an application of Wein's Law that states the following:

, where is the wavelength of maximum emission of the object (measured in ), and is the temperature in . Since the wavelength and the temperature are inversely proportional, if we double the temperature, we must cut the wavelength by the same proportion. Therefore, the temperature must be halved.

Stefan-Boltzmann's equation for a blackbody states:

, where is the energy emitted each second, is the Stefan-Boltzmann constant, and is the temperature of the blackbody. Therefore, if we triple the temperature, the energy will increase by a factor of

The kinetic theory of gas states:

. Whenever the velocity of the individual gas particles is larger than the escape speed of the planet,

, the gas particles will leak into space and deplete the atmosphere. The physical property that determines this is the mass of the planet.