Velocity of the ring wraiths relative to the air:

The speed
is what we want to find - this is the speed at which the wraiths are flying in the air.
(Note:
denotes velocity, while
denotes speed)
Velocity of air relative to the ground:

The ring wraiths want their trajectory to be due north, which means their velocity relative to the ground should be

To an observer on the ground,
is the speed at which the wraiths would appear to be moving in the air.
The relative velocities satisify



Given that t<span>he expression

represents the total length across the front of the mansion. Let the length of side I be a, then

</span>
Answer:
15/2
Step-by-step explanation:
hope it helps (•‿•)
Answer:
c
Step-by-step explanation: