(a) The gravitational force between 2 blocks is F what would happen if a mass of both the blocks as well as distance between them is doubled?
(b) A body is weightless at the centre of earth. why?
(a) The gravitational force between 2 blocks is F what would happen if a mass of both the blocks as well as distance between them is doubled?
(b) A body is weightless at the centre of earth. why?
(a)
According to Newton's Law of Gravitation the force of gravitation between two objects separated by a certain distance is given as
F = GmM / r2
now for the second case
F' = Gm'M' / r'2
where
M' = 2M
m' = 2m
and
r' = 2r
so, we get
F' = G(2m)(2M)/ (2r)2 = (4/4)[GmM/r2]
thus,
F' = F
the gravitational force remains the same.
(b)
The body experiences weightlessness at the center of the Earth because the acceleration due to gravity (g) is zero there. This is because as
g' = g(1- d/R)
and if d = R
g' = 0
So, Earth exerts no gravitational pull at its center making an object weightless.
(a)
According to Newton's Law of Gravitation the force of gravitation between two objects separated by a certain distance is given as
F = GmM / r2
now for the second case
F' = Gm'M' / r'2
where
M' = 2M
m' = 2m
and
r' = 2r
so, we get
F' = G(2m)(2M)/ (2r)2 = (4/4)[GmM/r2]
thus,
F' = F
the gravitational force remains the same.
(b)
The body experiences weightlessness at the center of the Earth because the acceleration due to gravity (g) is zero there. This is because as
g' = g(1- d/R)
and if d = R
g' = 0
So, Earth exerts no gravitational pull at its center making an object weightless.
