Question

(d) (i) 1. define the term gravitational field strength. 2. give an expression for the gravitational field strength, g, at a height, h, above the surface of the earth and explain all the symbols used. (ii) an object is dropped from the top of a tall building. explain why 1. the gravitational field strength at the top of the building is the same as on the ground, 2. the acceleration of the object at the top of the building may not be the same as the acceleration near the ground.

Explanation:

the mass of the Earth, $R$ is the radius of the Earth, and $h$ is the height above the Earth's surface.
(ii) 1. Because the height of the building is small compared to the Earth's radius.

1. Due to the presence of air resistance which affects the net force on the falling object.

Answer:

the mass of the Earth, $R$ is the radius of the Earth, and $h$ is the height above the Earth's surface.
(ii) 1. Because the height of the building is small compared to the Earth's radius.

1. Due to the presence of air resistance which affects the net force on the falling object.