If gravity is the only force present, what is the total mechanical energy of a
rock falling off a cliff at a time when its potential energy is 500 J and its
kinetic energy is 600 J?
A. 500 J
B. 100 J
C. 600 J
D. 1,100 J

(D) is correct option.

Explanation:

At a particular time, the potential energy of a rock is 500 J and its kinetic energy is 600 J.

It is required to find the mechanical energy of the rock. Mechanical or total energy is the sum of kinetic and potential energy. So,

TE = K+ P

TE = 500 J + 600 J

TE = 1100 J

So, the total mechanical energy of a  rock is 1100 J. Hence, the correct option is (D).

the earths atmosphere is made up of nitrogen and oxygen. solids can turn into gasses through a process called sublimation. sublimation is the transition of a substance directly from the solid to the gas phase, without passing through the intermediate liquid phase.

hope this : d

an electric circuit