Question

please answer fast!
I'll mark brainlist.​

Answer 1

Answer:

at centre of the earth force due to upper half cancle out the force due to lower half . that's why g is zero here.

Answer 2

Answer:

because , at the center of the earth the mass exerting force on the body becomes zero and also redius also becomes zero at the center of the earth

you can see formula of g under the surface of the earth = g (1-D/R) , where D is depth and R is redius at center depth becomes redius hence g (1-R/R) = 1-1 =0