Thank you for posting your question here at brainly. Below is the solution:
To find the circumference (orbit) of an object, you use Pi x Diameter. <span>As you have the circumference of B, you divide it by Pi to get the Diameter. </span> <span>So 120 divided by 3.141592654 = 38.2 minutes for the Diameter. </span>
<span>As' radius and Diameter will be 3x greater than B. </span> <span>38.2 x 3 = 114.6 </span> <span>To get back to the orbital period, times 114.6 by Pi, and you will get 360 minutes. </span>
Nope. False. The shift in spectral lines reveals only 'radial' motion ... motion toward us or away from us. The spectrum carries no information related to motion across the line of sight.
