Power can be defined as the rate at which work is accomplished.
Option D is the correct answer.
<h3>
</h3><h3>
Power </h3>
The work done by an object in a given time interval is called the power of that object.
Suppose an external force F is applied to any object for the time interval T seconds. Due to this external force, the object will perform some amount of work for the time T seconds. This work W done by the object for the time interval T seconds is called the power of that object.
Power can be defined in mathematical term which is given below.

Thus the power can also be defined as the work done by the object per unit time interval.
Hence we can conclude that option D is the correct answer.
To know more about power, follow the link given below.
brainly.com/question/1618040.
Answer:
The frictional torque is 
Explanation:
From the question we are told that
The mass attached to one end the string is 
The mass attached to the other end of the string is 
The radius of the disk is 
At equilibrium the tension on the string due to the first mass is mathematically represented as

substituting values


At equilibrium the tension on the string due to the mass is mathematically represented as



The frictional torque that must be exerted is mathematically represented as

substituting values


The universe is 13.8 billion years old.
Answer:
temperature, atmosphere pressure,wind, topography, humidity etc