Motion is physics. motion is the displacement,distance,velocity, acceleration, time, and speed.
From the law of atmosphere

Where
= constant and is number density where the height y = 0cm
= Number density at height y=3cm
Kb = Boltzmann constant 


Re-arranging the equation to have the value of the gravity,


Since it is 30% of value above surface, therefore 






Therefore the correct answer is C.
Answer:
Correct
Explanation:
Because the light can't travel as quickly in the water as it does in the air, the light bends around the pencil, causing it to look bent in the water. Basically, the light refraction gives the pencil a slight magnifying effect, which makes the angle appear bigger than it actually is, causing the pencil to look crooked.
To solve this problem, we use the Law of Universal Gravitation:
F = Gm1m2/d^2
where m1 and m2 are two objects. In this case, earth and man. d is the distance between the objects. Lastly, G is the gravitational constant. Since the mass of the earth and man are constant, this is lumped up with G into k. The equation would be:
F = k/d^2
k = Fd^2

The radius of earth, d1, is equal to 6.371E+6 m. Thus, d2 = 2d1
(8E+2)(d1)^2 = F2(2d1)^2
(8E+2)(d1)^2 = 4F2(d1)^2
(8E+2)=4F2
F2 = 200 Newtons