Naw! Common sense should be common which is why it's called common sense...
Answer:
the object has least potential energy at mean position of the SHM
Explanation:
If a block is connected with a spring and there is no resistive force on the system
In this case the total energy of the system is always conserved and it will change from one form to another form
So here we will say that
Kinetic energy + Potential energy = Total Mechanical energy
As we can say that total energy is conserved so here we have least potential energy when the system has maximum kinetic energy
So here we also know that at mean position of the SHM the system has maximum speed and hence maximum kinetic energy.
So the object has least potential energy at mean position of the SHM
Explanation:
Formula for maximum efficiency of a Carnot refrigerator is as follows.
..... (1)
And, formula for maximum efficiency of Carnot refrigerator is as follows.
...... (2)
Now, equating both equations (1) and (2) as follows.
=

= 
= 
= 2.5
Thus, we can conclude that the ratio of heat extracted by the refrigerator ("cooling load") to the heat delivered to the engine ("heating load") is 2.5.
Answer:
C. a disturbance that travels through a medium with a transfer of energy and without a transfer of matter
Explanation:
A wave is any disturbance that transfers energy from one location to the other via a substance called medium. It is important to note that a wave only conveys energy and not matter. For example, sound wave is a type of wave that carries sound energy from one place to another via mediums such as water, air etc.
Hence, according to this question, a wave can be described as a disturbance that travels through a medium with a transfer of energy and WITHOUT A TRANSFER OF MATTER.