What do we now understand to be the primary difference between normal galaxies and active galaxies?

Robin is swinging back and forth from a trapeze. in which of the following situations is his kinetic energy being transformed into potential energy

Scientists and engineers design new technologies to solve problems. often, a new technological design will contain a flaw. which of the following is true about such a flaw? a. it should be studied so that the design can be fixed or a new design can be proposed. b. it means that the problem being investigated cannot be solved. c. it means that the people who proposed the design should not be scientists or engineers. d. it makes the technological design useless.

Earthquakes and volcanic eruptions are examples of rapid events that are caused by the movement of earth's mountain building is a much more slow process, which is caused by the movement of earth's a. ocean tides; crustal plates b. ocean tides; winds c. crustal plates; crustal plates d. crustal plates; ocean tides