Which country or region is coal-rich and oil-poor?

Sort the images based on whether there's a force of attraction or repulsion between the magnets shown. attraction repulsion

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?

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?