MHB Multivariable conservative field

Click For Summary
To find a conservative field F where the line integral ∫F ds equals zero without C being a closed path, one can consider scenarios like the force of gravity. For example, if an object is moved vertically and returns to the same height, the work done by gravity is zero, indicating that the potential energy remains unchanged. This illustrates that conservative fields can have zero work done even when the path is not closed. Such examples demonstrate the properties of conservative fields in physics. Understanding these principles is essential for applying concepts of work and energy in various contexts.
kenporock
Messages
3
Reaction score
0
Goodnight,

How can I find a conservative field F, such that ∫F ds = 0 without C being a closed path
Can i have some examples ?
 
Physics news on Phys.org
kenporock said:
Goodnight,

How can I find a conservative field F, such that ∫F ds = 0 without C being a closed path
Can i have some examples ?

Hi kenporock, welcome to MHB! (Wave)

Consider the force of gravity.
Now move an object around, such that it ends up on the same height it had at the beginning.
The work done by gravity $∫\mathbf F\cdot d\mathbf s$ is then zero.
That is, the object has the same potential energy again.
 
There are probably loads of proofs of this online, but I do not want to cheat. Here is my attempt: Convexity says that $$f(\lambda a + (1-\lambda)b) \leq \lambda f(a) + (1-\lambda) f(b)$$ $$f(b + \lambda(a-b)) \leq f(b) + \lambda (f(a) - f(b))$$ We know from the intermediate value theorem that there exists a ##c \in (b,a)## such that $$\frac{f(a) - f(b)}{a-b} = f'(c).$$ Hence $$f(b + \lambda(a-b)) \leq f(b) + \lambda (a - b) f'(c))$$ $$\frac{f(b + \lambda(a-b)) - f(b)}{\lambda(a-b)}...

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
6K
  • · Replies 24 ·
Replies
24
Views
3K
  • · Replies 9 ·
Replies
9
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
13
Views
4K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K