Answer:
The assumptions we make when we infer the mass of a galaxy cluster from observations of the spectra of its constituent galaxies is thermal hydrostatic equilibrium
Explanation:
In galaxy cluster observation, thermal X-ray emission from the hot intracluster gas measures directly the gas density and temperature distributions within the cluster. This hot gas is confined by and expected to trace the underlying three-dimensional gravitational potential. Under the assumption of thermal hydrostatic equilibrium, these gas properties may be used to infer the cluster total mass distribution.
Hence, the assumptions we make when we infer the mass of a galaxy cluster from observations of the spectra of its constituent galaxies is thermal hydrostatic.
Object A at 40
degrees C and object B at 80 degrees C are placed in contact with each other.
The heat flow will flow from the Object B to the object A because of temperature
difference. To attain equilibrium, the heat flow must flow form a higher
temperature to a lower temperature.
D is the correct answer. Chemical reaction rates won't always be constant, you can change the rate of a chemical reaction. Factors that affect chemical reaction rates would be temperature, the concentration (pressure) of the reactant, or just the general surface area (crushing a reactant would be an example). Solvent polarity can also decrease the rate of a chemical reaction. Therefore, A, B, and C are true, leaving D as the answer.
Baking soda and vinegar
explosions
rust
fireworks