assertion:at the centre of the earth a body has centre of mass but no centre of gravity
Reason: This is becuse g=0 at the centre of the earth
Please explain it also
1i think both are correct ... i mean option A.
as we move h distance below earth,
acc due to gravity is given by : g' = go[1-h/R]
so wen h=R at the center, g'=0.
but centre of mass is the property of the body ...it will always be there
wherver we take the body....
so is it A?
1had done a blunder!
realised later..
the h in the above g' expression is <<<R.
but that wont effect the result..
wen, h=R, the mass inside : m' = ME(R-h)3/R3 becomes zero.
so, field is zero.
think of the graph....for field vs dist from center for a uniform solid sphere.
3center of gravity is the pt at which the whole weight is assumed to act.At the center of the earth W=0; and therefore the object doesnt have center of gravity.