GravitationHard
Question
A small body of superdense material, whose mass is twice the mass of the Earth but whose size is very small compared to the size of the Earth, starts from rest at a height H << R above the Earth′s surface, and reach the Earth′s surface in time t. Then t is equal to
Options
A.
B.
C.
D.
Solution
Acceleration of small body w.r.t. earth = g-(-2g) = 3g
Now from second equation of motion
H =
(3g)t2 ⇒ t = 
OR
= 
gt2 ⇒ t = 
Now from second equation of motion
H =
(3g)t2 ⇒ t = OR
= gt2 ⇒ t = Create a free account to view solution
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