All Questions
105
questions
0
votes
4
answers
163
views
What does the $F$ in Newton's second law equation mean?
This is a super simple question: does $F$ represent the net force exerted on an object or the force it exerts on another object as a result of momentum? Say a ball is rolling. In this specific ...
- 539
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
0
votes
0
answers
47
views
What exactly is force - apart from "the ability to do work"? [duplicate]
Does force - any kind - have an identity of its own apart from the set of effects it brings about? Or is it just "that which" ... "causes"; does this and that, makes certain ...
0
votes
1
answer
66
views
What is difference between normal force and reaction force? [duplicate]
according to my book the perpendicular component of reaction force is called normal force when there is contact between two bodies. I can not understand that how for example when we jump we pushes the ...
user379089
0
votes
2
answers
175
views
What is normal force and when it acts?
what are contact forces and according to: https://www.physicsclassroom.com/class/newtlaws/Lesson-2/Types-of-Forces
it says there are 6 types of contact forces. I am having doubt with applied force and ...
user379089
0
votes
2
answers
404
views
Difference between moment and couple
What is the exact difference between a moment and a couple? In some YouTube channels and books, they say the moment of a force produces a translational as well as rotational motion whereas the concept ...
1
vote
1
answer
90
views
Relation between Force and Potential in a relativistic context
In a relativistic context we define the four-force as, $$\frac{\mbox{d}}{\mbox{d}s}p=F$$ In the particle frame the four-force must have the form $$F=\left(0,\ \mathbf{f}\right)$$ As it must be ...
- 21
2
votes
2
answers
87
views
Are the definitions of force and acceleration circular? [duplicate]
Force is defined by acceleration , and acceleration requires the determination of" inertial frames".
But an inertial frames also requires the knowledge of forces which requires measuring ...
- 93
1
vote
2
answers
557
views
What is actually the clear, precise and world-wide accepted definition of TENSION FORCE?
This is a long post, but only because I have explained the scenario very very clearly,90 percent of this post is explaining you a simple situation,my doubt is only 5-6 lines at the very end of this ...
- 161
0
votes
2
answers
102
views
How can work be a function of position when non-conservative forces don't act the same way at each point?
My textbook and wiki/online articles all claim that work is given by the integral
$$W=\int_\gamma\vec{F}\boldsymbol{\cdot}\text{d}\vec{s}$$
where the $\text{d}\vec{s}$ is some infinitesimal step along ...
- 179
1
vote
2
answers
1k
views
What is the difference between work done against gravity and work done by gravity?
Work done "BY" a force,from my understanding,is:
•positive when the direction of displacement is same as the direction of force.
•negative when the direction of displacement is opposite to ...
- 57
-1
votes
2
answers
99
views
Motivation for definition of work [closed]
Why do we take the dot product in the work energy theorem? Consider the integral
$$\int\vert\vec F\vert\vert d\vec r\vert$$
Why don't we define this to be work done for example, instead of $\int\vec F\...
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:
$$dw=s.df \ \ ?$$
5
votes
6
answers
2k
views
What actually is impulse?
In my textbook it is mentioned that “impulse is used to get an idea of about the change in dynamical state of a moving particle”,but what does impulse actually mean?
- 79
-1
votes
3
answers
60
views
Definition on type of work [closed]
A man carries a bag hanging it in his hand and he moves horizontally. The bag does not move up or down. What is the work done on the bag? The man gets tired after some time of the movement. Why?
