Which is a biological sign of aging?

Loss of hearing of higher frequencies

Wrinkles appearing due to exposure to the sun's ultraviolet rays,

Decline in female fertility.

Hair turning gray.

Breakdown of joint cartilage

Explanation:

In humans ageing is sum of all the changes in the human body over time. The changes include physical, psychological, and social changes. Some of the effects are listed below:

Loss of hearing of higher frequencies

Wrinkles appearing due to exposure to the sun's ultraviolet rays,

Decline in female fertility.

Hair turning gray.

Breakdown of joint cartilage.

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