46) A tunnel is dug across the diameter of earth A ball is released from the surface of - Physics - Gravitation

Question

46) A tunnel is dug across the diameter of earth A ball is released
from the surface of Earth into the tunnel The velocity of ball when
it is at a distance R 2 from the centre of earth is (where R =
radius of Earth and M = mass of earth)
( 1 )   3 G M 4 R ( 2 )   2 G M 3 R ( 3 )   G M 2 R
( 4 )   2 G M R

Shobhit Mittal · Accepted Answer

Dear Student,

PE at the surface =-GMmRPE at the point R/2=-GM2R33R2-R24=-11GMm8R∆U=-WW=-∆U=--11GMm8R+GMmR=3GMm8Rfrom WET mv22=3GMm8Rv=3GM4Roption 1Regards

46) A tunnel is dug across the diameter of earth. A ball is released from the surface of Earth into the tunnel. The velocity of ball when it is at a distance R 2 from the centre of earth is (where R = radius of Earth and M = mass of earth) ( 1 ) 3 G M 4 R ( 2 ) 2 G M 3 R ( 3 ) G M 2 R ( 4 ) 2 G M R