Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Q&A

What is virtual work?

+3
−0

$$\sum_i F_i \cdot \delta r_i$$ is virtual work when internal force is $0$. For that reason, $$\sum_i F_i \cdot \delta r_i = 0$$

Here internal force stands for what?

When a object's displacement is imaginary then, that object's work is virtual work. But, how a object's displacement can be imaginary? Is that only theoretical (just to apply formulas)?

What I understood from the video that is, when we move a object in a much smaller amount of displacement than, that's called virtual displacement or imaginary displacement. For moving that, we have applied some forces hence, that force is called virtual work. Is that correct?

History
Why does this post require moderator attention?
You might want to add some details to your flag.
Why should this post be closed?

0 comment threads

1 answer

+1
−0

To understand virtual work you should understand virtual displacement first,

The wiki I have linked in first paragraph describes virtual displacement deeply. Usually we write $\delta$ or $d$ to say infinitesimal, now the question is infinitesimal what? As the OP wrote in question that $\sum_i F_i\cdot \delta r_i$ so when there's infinitesimal displacement there's infinitesimal work.

So if an object done infinitesimal displacement by force F then the work on that object is called virtual displacement.

Internal force is force done on that object. If force is huge then the displacement will be large but if force is infinitesimal (assuming force to be $0$) then displacement will be also infinitesimal that's what infinitesimal work.

If you want to read more about Virtual Work then visit Wiki page

The virtual work is called D'Alembert principle

History
Why does this post require moderator attention?
You might want to add some details to your flag.

0 comment threads

Sign up to answer this question »