Question

Find the value of the acceleration due to gravity at a height of 12,800 km from the surface of the earth Earth's radius = 6400 km. (ii) State Newton's law of gravitation and write the mathematical equation describing itCBSE Class IX Science SA 2 (3 Marks)

Answer 1

  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.

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

Answer 2

Answer:

answer ->1.0888m/s2

Explanation:

hope this helps you......