Answer:
1.85 J/K
Explanation:
The computation of total change in entropy is shown below:-
Change in Entropy = Sum Q ÷ T
= 

= -3.12 + 4.97
= 1.85 J/K
Therefore for computing the total change in entropy we simply applied the above formula.
As we can see that there is heat entering the reservoir so it will be negative while cold reservoir will be positive else the process would be impossible.
Answer:
magnification will be -0.025
Explanation:
We have given the radius of curvature = 12 cm
And object distance = 3 m
So focal length 
Now for mirror we know that
So 

v = 0.750 m
Now magnification of the mirror is 
Answer:
μ = 0.692
Explanation:
In order to solve this problem, we must make a free body diagram and include the respective forces acting on the body. Similarly, deduce the respective equations according to the conditions of the problem and the directions of the forces.
Attached is an image with the respective forces:
A summation of forces on the Y-axis is performed equal to zero, in order to determine the normal force N. this summation is equal to zero since there is no movement on the Y-axis.
Since the body moves at a constant speed, there is no acceleration so the sum of forces on the X-axis must be equal to zero.
The frictional force is defined as the product of the coefficient of friction by the normal force. In this way, we can calculate the coefficient of friction.
The process of solving this problem can be seen in the attached image.
Force is mass times acceleration. This means an object with a larger mass needs a stronger force to be moved along at the same acceleration as an object with a small mass