If the distance between two objects is doubled,the gravitational force between them :

Write True or False for the following statement:
If a spring balance holding a heavy object is released,it will read zero weight.

According to Newton's law of gravitation,every particle of matter attracts every other particle. But bodies on the surface of the Earth never move towards each other on account of this force of attraction. Why?

State any one phenomenon related to the universal law of gravitation.

If your weight on the Earth is $450 N$,calculate your weight on planet Mars. (Radius of Mars $= 4.3 \times 10^{6} m$,mass of Mars $= 6 \times 10^{23} kg$ and gravitational constant $G = 6.67 \times 10^{-11} Nm^{2} kg^{-2}$). Take acceleration due to gravity on Earth as $10 m s^{-2}$.

An object is placed one by one in three liquids having different densities. The object floats with $\frac{1}{9}$, $\frac{2}{11}$, and $\frac{3}{7}$ parts of its volume outside the liquid surface in liquids of densities $d_1$, $d_2$, and $d_3$ respectively. Which of the following statements is correct?