Answer:
c.
Explanation:
We are given that 
Acceleration due to gravity on the moon=
Acceleration due to gravity on the earth=

Net force due to am on an object on moon=
There is no friction and no drag force and there is no gravity involved 
Then, the force acting on an object on earth=
 (given)
(given)


Hence, option c is true.
 
        
             
        
        
        
Answer:
The surface tension is 0.0318 N/m and is sufficiently less than the surface tension of the water.
Solution:
As per the question:
Radius of an alveolus, R = 
Gauge Pressure inside, 
Blood Pressure outside, 
Now,
Change in pressure, 
Since the alveolus is considered to be a spherical shell
The surface tension can be calculated as:


And we know that the surface tension of water is 72.8 mN/m
Thus the surface tension of the alveolus is much lesser as compared to the surface tension of water.
 
        
             
        
        
        
Without an atmosphere, the equatorial curve would show minimum daily values on the solstices in June when the sub-solar point is located at 23.5°N and in December when the sub-solar point is at 23.5°S latitude.
Explanation:
At the sub-solar point, the sun strikes directly at the surface with an angle of 90 degrees at a given point.
Solistice refers to that point in time when the sun’s zenith is located at the farthest point from the equator.  
During summer solistice on June 21, the sun’s zenith reaches northernmost point, sub-solar point is fixed at 23.5°S Tropic of Cancer making the earth tilt 23.4 degrees
During winter soliscitse on December 21, the sub-solar point is fixed at)  Tropic of Capricorn.
 
        
             
        
        
        
If the light from the sun has higher frequencies from one side of the sun than from the other side, it is proof that the Sun is rotating.
Doppler effect states that, if a person is standing still and a source ( sound / light ) is moving towards him, the frequency of the wave emitted from the object will increase and if the source ( sound / light ) is away from him, the frequency of the wave emitted from the object will decrease. 
So, if the light from the sun has higher frequencies from one side of the sun than from the other side, it means that the Sun is rotating. The higher frequencies points are the points that rotating towards Earth and lower frequencies points are the points that rotating away from Earth.
Therefore, if the light from the sun has higher frequencies from one side of the sun than from the other side, it is proof that the Sun is rotating.
To know more about Doppler Effect
brainly.com/question/15318474
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