It’s cause by the fact that the earth is tilted 23.5 degrees
Explanation :
The forces acting on hot- air balloon are:
Weight, (W)
Force due to air resistance, (F)
Upthrust force, (U)
Its weight W is acting in downward direction. The upthrust force U acts in upward direction. When the balloon is moving upward, the air resistance is in downward and vice versa.
In this case, the hot-air balloon descends vertically at constant speed.
so, 
and 
so,
....................(1)
when it is ascending let the weight that it is releasing is R, so
..........(2)
solving equation (1) and (2)

2F is the weight of material that must be released from the balloon so that it ascends vertically at the same constant speed.
The centripetal acceleration is responsible
for the artificial gravity because the acceleration of an object moving in constant
circular motion causing from net external force is called centripetal
acceleration. It defines to the center or seeking the center.
Given the following:
Cylindrical space station
diameter = 275 meters; 137.5
meters for the radius
Standard gravity =
9.80665 m/s²
Using the formula:
w² x r =g
w² = g / r
w² = 9.80665 m/s²
/ 137.5 m
w² = 9.80665 m/s²
/ 137.5 m
w² = 0.0713 s²
Then take the roots
w = 0.267 this is radians per
second / 2 x (3.1416 which is the pi)
w = 0.0424 rps convert to rpm
w = 0.0424 r/s (1minute / 60
seconds)
w = 7.08 x 10⁻⁴ revolutions per minute
Answer:

Explanation:
P = Acoustic power = 63 µW
r = Distance to the sound source = 210 m
Acoustic power

Threshold intensity = 
Ratio

Ratio of the acoustic intensity produced by the juvenile howler to the reference intensity is 113.68
Answer:
artificial: light bulb, flash light, computer screens. natural: sun, stars, fires.