Shorter wavelengths (higher frequencies) correspond to higher energies and thus hotter star temperatures.  Sue sees a star with a high frequency. Erin sees a star with a low frequency. The hotter star belongs to Sue or Erin?
Sue

The hotter a main sequence star is, the brighter it is.  Stars that are colder are also dimmer or brighter?
dimmer

The smaller its mass is, the greater its acceleration for a given amount of force.  What happens to a light car when it has the same power as a heavy car accelerates faster or accelerates slower?
accelerates faster

A decrease in greenhouse gas levels decreases global temperature and an increase raises global temperature.  If greenhouse gas were to be halved, the global temperature would increase or decrease?
decrease