Question

Two bodies of masses 2kg and 5kg are dropped from a tower. Assuming that there is no air, compare the time in which these bodies will reach the ground.

Answer 1

Answer:

ratio of both the times is zero

Answer 2

Given:

Two bodies of masses 2kg and 5kg are dropped from a tower.

To find:

Ratio of time taken to reach ground?

Calculation:

Since there is no air-resistance, we can say that the acceleration of both the objects is constant and equal to g = 9.8 m/s².

So, applying 2nd Equation of Kinematics:

$\rm h = ut + \dfrac{1}{2} g {t}^{2}$

• Value of 'u' = 0 m/s.

$\rm \implies h = 0 + \dfrac{1}{2} g {t}^{2}$

$\rm \implies h = \dfrac{1}{2} g {t}^{2}$

$\rm \implies t = \sqrt{ \dfrac{2h}{g} }$

• Since there is no 'mass' factor in the equation, we can say:

$\rm \implies t \propto {m}^{0}$

So, both 2kg and 5kg mass will reach ground at same time.

So, ratio of the time will be 1 : 1 .