Why is it difficult to hold a school bag having a strap made of a thin and strong string?

If the masses of two objects are almost equal then what will be the acceleration due to the force of gravitation ?

What is the reason for the occurrence of tides in the oceans ?

What do you mean by acceleration due to gravity?

What do you mean by free fall?

Write the formula to find the magnitude of the gravitational force between the earth and an object on the surface of the earth.