GATE-2018 (24) :Wyllie – Time average equation

CSIR-NET 2014

118. The densities of the Earth and Mars are in the ratio 14:10. The rate of decrease of the gravity field of Mars on its surface with elevation would be..

a)0.31gal/km 

b) 0.25gal/km 

c)0.22gal/km

d)0.10gal/km

Solution:

(1). Earth

In free air correction (the gravity decreases with elevation increases).

= 0.3086 mGal/m

=0.3086 Gal/km

The densities of the Earth and Mars are 14:10

Earth 14 ------0.3086 gal/km

Mars 10--------?

cross multiplication

14* x = 10* 0.3086

x= 3.086/14

x=0.2204

In Mars = 0.2204 gal/km