Correct Answer - Option 3 : g decreases, G remains constant
Concept:
Law of Universal Gravitation
It states that all objects attract each other with a force that is proportional to the masses of two objects and inversely proportional to the square of the distance that separates their centres.
It is given mathematically as follows:
\(F = \frac{Gm_1m_2}{R^2}\)
Where m1 and m2 are the mass of two objects, G is the gravitational constant and R is the distance between their centres.
- The gravitational constant G establishes a relationship between gravitational force, mass, and distance.
- The value of G is 6.67 × 10-11 N kg-2 m2.
Acceleration Due to Gravity:
- The force of attraction exerted by the earth on a body is called gravitational pull or gravity.
- We know that when a force acts on a body, it produces acceleration. Therefore, a body under the effect of gravitational pull must accelerate.
- The acceleration produced in the motion of a body under the effect of gravity is called acceleration due to gravity, it is denoted by g.
- The acceleration due to gravity on the surface is given as
\(g = \frac{{GM}}{{{R^2}}} \) -- (1)
G is universal constant, M is mass, R is radius of earth.
Explanation:
So, G is a universal constant, it will remain constant.
g varies with distance from earth. At some altitude h
\(g = \frac{{GM}}{{{(R+h)^2}}} \)
So, as h increase, the denominator increase, and hence g decreases
So, the g decreases, G remains constant is the correct option.