All Questions
10
questions
0
votes
4
answers
91
views
What are internal and external forces?
what is internal and external force? How do I decide what forces are internal and external?
in work-energy theorem and conservation of mechanical energy, do we consider internal, external, or both ...
- 91
1
vote
2
answers
605
views
Why does small work done mean $dw=f.ds$ and why not $dw=df.ds$ and why not $dw=s.df$? [duplicate]
Work, power and energy questions.
Why does small work done mean:
$$dw=f.ds$$
and why not:
$$dw=df.ds$$
and why not:
$$dw=s.df \ \ ?$$
4
votes
3
answers
815
views
How can an object do work?
I read in many sites that the concept of mechanical energy is the ability of an object to do work, but how can an object do work? Isn't it rather the force applied to that object the one that produces ...
- 179
-3
votes
1
answer
61
views
Is energy, as we know it, "persistent"? [duplicate]
Suppose I raise a ball (with my hand) to some height. I am doing some work against gravity and storing potential energy in the ball.
However, once I loosen my grip, or just sweep my hand away from ...
- 71
4
votes
7
answers
629
views
What comes first: Work or kinetic energy?
Suppose we have a body initially at rest. Now a force ($F$) is continuously applied on it and it gets displaced by some distance $x$.
My tutor said that from work energy theorem it gains kinetic ...
- 8,220
3
votes
7
answers
2k
views
Work done when lifting an object at constant speed
A previous post (What Is Energy? Where did it come from?) defines work qualitatively as "a process in which energy is transformed from one form to another form". And mathematically, work is ...
3
votes
9
answers
4k
views
Why is work equal to force times displacement?
This is how I think of what work is.I am sure I am wrong somewhere because I shouldn't be coming to the conclusion that I am coming to.It would be helpful if you would point out where this conceptual ...
- 1,033
-1
votes
2
answers
201
views
What is work definition exactly? [duplicate]
i learn about work and most book define force x distance. The definition given not very informative and the book don't describe much about it. All they do is give above definition and then a lot of ...
- 17
8
votes
5
answers
2k
views
Confusion between two different definitions of work?
I'm doing physics at high school for the first time this year. My teacher asked us this question: if a box is slowly raised from the ground to 1m, how much work was done? (the system is only the box)
...
6
votes
5
answers
2k
views
What exactly is work?
What exactly is work? My book confuses me:
a force can lift an object to a height h, or it can accelerate an object through gravity. In all these cases, a force displaces an object and change the ...
- 1,361