Simplifying the Work Done Equation: x(e^y) + (z+1)(e^z) - (e^z) + k

  • Thread starter Thread starter chetzread
  • Start date Start date
  • Tags Tags
    Work Work done
Click For Summary
The discussion centers around the equation for work done, questioning whether the correct expression should be 2x(e^y) + (z+1)(e^z) - (e^z) + k or just x(e^y) + (z+1)(e^z) - (e^z) + k. It is clarified that the author is correct in stating the latter, as common terms should not be added indiscriminately. Participants agree that simply summing the right-hand sides of the equations is incorrect, and they emphasize the importance of maintaining the integrity of the expressions. The consensus is that expressions should be handled with care to avoid misinterpretation in calculus. The discussion highlights the need for precision in mathematical problem-solving.
chetzread
Messages
798
Reaction score
1

Homework Statement


for the work done θ , after combining all three , the work done should be = 2x(e^y) + (z+1)(e^z) - (e^z) + k , am i right ?
why the author stated it is x(e^y) + (z+1)(e^z) - (e^z) + k ?
There's x(e^y) in equation (i) and (ii)

Homework Equations

The Attempt at a Solution


θ= (x)(e^y) + f(y,z) + (x)(e^y) + g(x,z) + (z+1)(e^z) - (e^z) + h(x,y )
= 2(x)(e^y) + (z+1)(e^z) - (e^z) + k
 

Attachments

  • 12.jpg
    12.jpg
    33.2 KB · Views: 404
  • 13.jpg
    13.jpg
    12.6 KB · Views: 370
Physics news on Phys.org
chetzread said:
the work done should be = 2x(e^y) + (z+1)(e^z) - (e^z) + k , am i right ?
why the author stated it is x(e^y) + (z+1)(e^z) - (e^z) + k ?
There's x(e^y) in equation (i) and (ii)
No, the author is right. You shouldn't simply add the RHS of the equations. The expressions which are common don't need to be added. In your example, if you had ##2xe^y## ( like you thought), you wouldn't get ## \frac {\partial \phi}{\partial x} = e^y## and ## \frac {\partial \phi}{\partial y}= xe^y##
 
  • Like
Likes chetzread
I would never have solved it this way. I would have expressed everything in terms of t.
 
Chestermiller said:
I would never have solved it this way. I would have expressed everything in terms of t.
Exactly, I too would have done the same.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

Similar threads

Replies
7
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
6
Views
2K
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 8 ·
Replies
8
Views
806
  • · Replies 6 ·
Replies
6
Views
2K