The gravitational force decreases as the between two objects increases.

distance
mass
force

Answer : The correct option is, Distance

Explanation :

Gravitational force : It is a type of force that acts between the two masses which are separated by the distance.

The formula used for gravitational force is,

where,

= gravitational force

G = gravitational constant

and are the masses of the objects

r = distance between the two object

From this we conclude that the gravitational force decreases as the distance between two objects increases because there is an inverse relationship between the gravitational force and the distance between the two objects.

Hence, the correct option is, Distance

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