Work Energy And Power Question 301
Question: If only conservative forces are working in the system and we apply some external force
Options:
A) $ W _{ext}=\Delta U $ (always)
B) $ {W _{conservative}}=-\Delta U $ (always)
C) $ W _{ext}=\Delta U+\Delta KE $ (always)
D) $ {W _{conservative}}=-\Delta KE $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] If only conservative forces are acting in the system.
$ \Rightarrow $ $ W _{ext}=\Delta U $ (If body moves without acceleration)
$ W _{ext}=\Delta U+\Delta KE $ (if body moves with acceleration)
$ \Rightarrow $ $ {W _{conservative}}=-\Delta U $ (always)
