How does mass affect the time it takes an object to hit the ground?

For an ideal condition The Mass does not  affect the time taken by an object to hit the ground.

As the ground attracts all object with the same acceleration due to gravity 9.8 m/s². so all objects that  drop from a certain height hit the ground at same time .

But in real condition there is air resistance present ,due to which objects of different masses take different time to hit the ground.

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s