"a wheel is rolling without slipping on a flat surface". if the diameter of the wheel is 1 meter, how far does the hub of the wheel move when the wheel turns once?

Which type of basaltic lava flow has a fairly smooth

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?

In which of these cases are the two wave points considered to be in phase with each other?