An astronaut at rest on Earth has a heartbeat rate of 65 beats/min. When the ast
ID: 1284973 • Letter: A
Question
An astronaut at rest on Earth has a heartbeat rate of 65 beats/min. When the astronaut is traveling in a spaceship at 0.82c, what will this rate be as measured by the following: (a) an observer also in the shipbeats/min
(b) an observer at rest on Earth
beats/min
An astronaut at rest on Earth has a heartbeat rate of 65 beats/min. When the astronaut is traveling in a spaceship at 0.82c, what will this rate be as measured by the following: (a) an observer also in the ship
beats/min
(b) an observer at rest on Earth
beats/min
(a) an observer also in the ship
beats/min
(b) an observer at rest on Earth
beats/min
Explanation / Answer
an observer comoving with the astronaut will measure a frequency of 65beats/min since the two are in the same reference frame
an observer on the earth will measure the astronaut's time to be dilated by a factor
t(observed) = t(rest)/Sqrt[1-(v/c)^2] = t(rest)/Sqart[1-(0.89c/c)^2] = 2.19 t(rest)
this means an EArth observer will measure the time between heart beats to be 2.19 times longer than will be measured by the astronaut on the ship
thus, if the astronaut measures 65 beats in 1 minute, we will observe 65/2.19 beats in one (earth based) minute = 29.6 beats