COMEDK Exam 2015 Solved Paper

Weight of stone at the surface of the earth, w=100N At height h from the surface of earth, gravitational acceleration,
gh=‌

g

(1+‌ h R )2

At depth d from the surface of the earth, gravitational acceleration,
gd=g(1−‌

d

R

)
According to question,
‌

‌ Weight at ‌h=R∕2

‌ Weight at ‌d=R∕2

=‌

mgh(‌ at ‌h=R∕2)

mgd(‌ at ‌h=R∕2)

‌=‌

‌ g (1+ h R )2 (‌ at ‌h=R∕2)

g(1−‌ d R )‌ at ‌(d=R∕2)

‌=‌

‌ 1 (1+ R∕2 R )2

1−‌ R∕2 R

=‌

4∕9

1∕2

=‌

8

9

=0.9
‌