A supersonic jet is 7,800 kilometers east of U. S. airspace. If the jet flies at a constant velocity of 1,300 kilometers per hour to the west, how much time will it take the jet to fly
one-third of the way to U. S. airspace?

Explain why the aperture of the spherical mirror should be small compared to the radius of curvature of the mirror.

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?

Which of the following is a measure of the amount of light a star directly emits?               a.  luminosity    b.  intensity    c.  wavelength    d.  brightness