một vật dao động điều hòa với phương trình x= 4cos(πt+π/6) . tìm tất cả những thời điểm vật đi qua vị trí cân bằng

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?

When you notice something that is happening, what are you making? a. an observation b. a law c. a theory d. an experiment

The international space station is traveling in a circular path around earth. which of the following is constantly changing? a.) mass b.) weight c.) velocity d.) speed