No force is necessary to keep a moving object moving (in a straight line at a constant speed).
Because the Moon has a very small surface area compared to other spacial geo-bodies, it has cooled down much faster than Earth. Any water on the moon would freeze.
Answer: Permanent magnets consist of multiple "ferromagnetic materials" I think that might be the answer, there weren't really any choices for me to choose from.
<h2>The temperature of the air is 66.8° C</h2>
Explanation:
From the Newton's velocity of sound relationship , the velocity of sound is directly proportional to the square root of temperature .
In this case The velocity of sound = frequency x wavelength
= 798 x 0.48 = 383 m/sec
Suppose the temperature at this time = T K
Thus 383 ∝
I
The velocity of sound is 329 m/s at 273 K ( given )
Thus 329 ∝
II
Dividing I by II , we have
= 
or
= 1.25
and T = 339.8 K = 66.8° C