5 facts of your own about crystal meth?​

Which of the following are appropriate acceleration units?

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?

Frequency of electromagnetic waves that a radio station is assigned. what do you call this type of wave?