Answer: b
Explanation:
When heat is released by the system i.e. system loses heat. So, we take it as negative -Q
When the work is done on the system then it is considered as negative work on the system i.e. -W
In this case, the plunger is pulled out, and work is done on the system. So, we take work as negative work -W
Correct option is b
Answer:
The value is 
Explanation:
From the question we are told that
The number of turns is N = 1000
The length is L = 50 cm = 0.50 m
The radius is r = 2.0 cm = 0.02 m
The current is I = 18.0 A
Generally the magnetic field is mathematically represented as
Here 
is the permeability of free space with value
So
=>
He made pioneering contributions to all fields of philosophy and science, he invented the field of formal logic, and he identified the various scientific disciplines and explored their relationships to each other. Aristotle was also a teacher and founded his own school in Athens, known as the Lyceum.
I believe that the answer to this would be B
Hope this helped
Look up pulleys problem through Khan academy and a video should pop up with a problem similar and you should be able to walk through it .
