Which of the following is the evidence to show that there must be a force acting on the earth and directed towards the sun?

$A$ man weighs $600\,N$ on Earth. What is his mass? $(g=10\,m s^{-2})$. On the Moon,his weight would be $100\,N$. What is the acceleration due to gravity on the Moon?

The value of acceleration due to gravity

State whether the following statement is true or false:
The force of attraction between two bodies is called gravity.

Two stones $A$ and $B$ are dropped from a multi-storey building. Stone $A$ is dropped from $100 \, m$ and at the same time stone $B$ is dropped from $50 \, m$ height. Both of them reach the earth at the same time. Will they have equal velocity while reaching the ground? Calculate and find out the answer (Take $g = 10 \, m s^{-2}$).

State the universal law of gravitation. Write the $SI$ unit of $G$.