Choose the correct alternative.

Acceleration due to gravity is:

Which of the following symptoms is not likely to afflict an astronaut in space?

1. swollen feet
2. swollen face
3. headache
4. orientational problem

A body weights \(63\) N on the surface of the earth. What is the gravitational force on it due to the earth at a height equal to half the radius of the earth?
1. \(98~\text N\) 
2. \(35~\text N\) 
3. \(63~\text N\) 
4. \(28~\text N\) 

Assuming the earth to be a sphere of uniform mass density, how much would a body weigh halfway down to the centre of the earth if it weighed \(250\) N on the surface?