This is physics and it says collision and elastic/inelastic i need help

What effects result when there is an impact between earth and an asteroid? check all that apply. a. massive flooding. b. extinction of many life forms. c.major earthquakes change in average global temperature. d. giant dust cloud

In which of the following is positive work done by a person on a suitcase

According to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does maria's voyage take according to samir?