A day on a distant planet observed orbiting a nearby star is 62.3 hours. Also, a
ID: 1313419 • Letter: A
Question
A day on a distant planet observed orbiting a nearby star is 62.3 hours. Also, a year on the planet lasts 28.5 Earth days.* Calculate the average angular speed of the planet about its own axis of rotation in radians per second, with the second as measured on Earth.
Calculate the average angular speed of the planet as it travels around its neighboring star, with the second as measured on Earth.
* In other words, for the purposes of unit conversion there are 24 hours in a day, 60 minutes in an hour, and 60 seconds in a minute, as it would for astronomers on Earth observing the planet.
Explanation / Answer
(a)
Angular speed = 2 pi / 62.3 = 1.744 *10-3 rad /sec about its own axis
(b)
avg angular speed = 2pi / 28.5 days = 2pi / (28.5*24*60*60) = 7.27 *10-5 rad /sec aroud the star