An astronaut at rest on Earth has a heart rate of 70 beats/min. When the astronaut is traveling in a spaceship at 0.90 c , what will this rate be as measured by (a) an observer also in the ship and (b) an observer at rest on Earth?

An astronaut at rest has a heart rate of 65 beats/min. What will her heart rate be as measured by an earth observer when the astronaut's spaceship goes by the earth at a speed of 0.60 c? 39 beats/min 52 beats/min O 108 beats/min O 81 beats/min

1. You are an observer in a 100-m long spacecraft traveling from the earth to the moon at 0.8c. (a)What is the proper length of the spacecraft? (b) For a proper time interval of 1 sec., the relativistic time interval for the spacecraft measured from the earth reference frame would be: (c)Time dilation does not apply to all time-dependent physical and biological processes. T/F? (c) What is the relativistic length, DL measured from the reference frame of earth? (d) An APOLLO crew left a flat mirror reflector on the surface of the moon (for all you deniers out there, in the 50th anniversary year of APOLLO 11!). If the average surface-to-surface distance from the earth to the moon is 3.83 x 10^8 m, then how long does it take moonlight to reach earth?

A spaceship approaching an asteroid at a speed of 0.77c launches a rocket forward with a speed of 0.27c relative to the spaceship. At what factor of the speed of light c is the rocket approaching the asteroid as measured by an astronaut on the asteroid?