Can u pls me with the 4th n 5th question

Atrain departs from its station at a constant acceleration of 5 m/s. what is the speed of the train at the end of 20s?

The solar panels used by mark function because of the photoelectric effect. light shines on the cells causing electrons to be ejected from the metal, which produces an electric current. at night on mars, no light will fall on the solar cells and no electric current will be generated. according to your notes, what type of light is typically needed to cause the photoelectric effect? a)visible b)ultraviolet c)infrared

Could we see a galaxy that is 20 billion light-years away?