The first law of thermodynamics leads us to conclude that A. disorder in the universe is increasing with the passage of time.
B. the total energy in the universe is decreasing with time.
C. it is theoretically impossible to convert work into heat with 100% efficiency
D. the total energy of the universe is constant.
E. the total energy in the universe is increasing with time.

D

Explanation:

D - The total energy in the universe is constant

The first law of thermodynamics states that heat is also another form of energy, and that thermodynamic processes are as a result, subjected to the principle of conservation of energy. The principle of conservation of energy is another way of boldly saying that heat energy cannot be created and neither can heat energy be destroyed.

I hope that's clear enough

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