Question

Find the value of acceleration due to gravity at a height of 80 km from the surface of earth

Answer 1

Answer:

Newton's law of Gravitation: F = G M m / d²

G = Universal Gravitational constant = 6.674 * 10⁻¹¹ N m²/kg²

M = Mass of a body

m = mass of the 2nd body

d = distance between the centers of mass of the two bodies

Let R = radius of Earth = 6,400 km

h = altitude above Earth = 12,800 km

d = distance from center of Earth = 19,200 km

We know that on the surface of Earth, gravity is:

g = G M / R² = 9.81 m/s²

g' = acceleration due to gravity at distance d = G M / d² => g'/g = R²/d² => g' = g R² / d² = 9.81 * 6400²/19200² = 1.09 m/s²

Explanation:

Newtons law of Gravitation states that the force of gravitational attraction between two bodies of mass M and m separated by a distance d, is proportional directly to the product of masses and inversely proportional to the square of the distance between them.