Which statements accurately describe plasmas? Check all that apply.
Plasmas can conduct electricity.
. Plasmas cannot be created.
Plasmas have a rigid shape.
Plasmas are created when a lot of energy is applied to a gas.
Plasmas contain ions and free electrons.

Atrain is traveling at 30.0 m/s relative to the ground in still air. the frequency of the note emitted by the train whistle is 262 hz. the speed of sound in air should be taken as 344 m/s. what frequency (f approach) is heard by a passenger on a train moving at a speed of 18.0 m/s relative to the ground in a direction opposite to the first train and approaching it? what frequency (f recede) is heard by a passenger on a train moving at a speed of 18.0 m/s relative to the ground in a direction opposite to the first train and receding from it?