According to Rahul any two bricks tied together would fall faster than a single one under the action of gravity by neglecting air resistance. Do you agree with
Rahul? Give a reason to support your answer.

Rahul is wrong.

Explanation:

From Newton's universal law of gravitation, we know that the force of attraction between two falling body masses is directly proportional to product of masses of two bodies and has an inverse proportional relation with the square of the distance between the masses.

If the 2 masses are M1 & M2, while distance between them is d, this can be written as;

F ∝ M1•M2

And F ∝ 1/d²

We also know that the acceleration due to gravity is given as;

g = GM/r²

Where;

M is the mass of earth

r is the radius of earth

From the above 3 formulas, we can deduce that the value of the acceleration due to gravity(g) is independent of the 2 masses of the falling body as it depends on only the mass of the earth and radius of the earth.

This means that the acceleration due to gravity will be the same whether the bricks are doubled or whether it remains single.

Thus, they will fall with same velocity in each case. So Rahul is wrong.

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.