The astronaut whose heart rate on Earth is 60 beats/min increases his velocity to v = 0.80 c.Now what is his heart rate as measured by an Earth observer?
A)36 beats/min
B)48 beats/min
C)75 beats/min
D)100 beats/min

Question

Quizplus · Accepted Answer

Due to time dilation in special relativity, the astronaut's heart rate as observed from Earth will decrease. The time dilation factor is given by the Lorentz factor, which is approximately 0.6 for v = 0.80c. Thus, the heart rate observed from Earth is 60 beats/min * 0.6 = 36 beats/min.

The Astronaut Whose Heart Rate on Earth Is 60 Beats/min