Physical change 1 is the answer
The characteristic of a circuit actually indicate how the circuit functions. When one designs a circuit they have a specific function in mind and must know how to combine components in order to fulfill this functions.
Missing question:
"Determine (a) the astronaut’s orbital speed v and (b) the period of the orbit"
Solution
part a) The center of the orbit of the third astronaut is located at the center of the moon. This means that the radius of the orbit is the sum of the Moon's radius r0 and the altitude (

) of the orbit:

This is a circular motion, where the centripetal acceleration is equal to the gravitational acceleration g at this altitude. The problem says that at this altitude,

. So we can write

where

is the centripetal acceleration and v is the speed of the astronaut. Re-arranging it we can find v:

part b) The orbit has a circumference of

, and the astronaut is covering it at a speed equal to v. Therefore, the period of the orbit is

So, the period of the orbit is 2.45 hours.
A) atomic number 7
B) 15
C) 6 c, 12 h, 6 o
D) o-8
S-16