Questions tagged [displacement]
343 questions
43
votes
6 answers
How much air needs to be displaced to generate an audible sound?
I'm reading a book where in one scene a wizard/alchemist teleports a scroll after reading.
He folded the parchment carefully and muttered a single cantrip. The note vanished with a small plop of displaced air, joining the others in a safe…
npst
- 543
36
votes
4 answers
What exactly is a virtual displacement in classical mechanics?
I'm reading Goldstein's Classical Mechanics and he says the following:
A virtual (infinitesimal) displacement of a system refers to a change in the configuration of the system as the result of any arbitrary infinitesimal change of the coordinates…
Gold
- 38,087
- 19
- 112
- 289
20
votes
9 answers
Why is small work done always taken as $dW=F \cdot dx$ and not $dW=x \cdot dF$?
I was reading the first law of thermodynamics when it struck me. We haven't been taught differentiation but still, we find it in our chemistry books. Why is small work done always taken as $dW=F \cdot dx$ and not $dW=x \cdot dF$?
Suzie Waters
- 339
14
votes
4 answers
Why doesn't constant acceleration give me total displacement?
I started learning 1D kinematics and learnt definitions of constant velocity and constant acceleration. I thought that if a particle is changing its velocity uniformly then it has constant acceleration. From this I tried to plot x-t graph from the…
Sai Varun
- 177
14
votes
8 answers
If application of force does not result in spatial movement, has work been done?
I'm trying to help my kids why their elementary-school physics. Their lesson today says that "work" is done only when a change in position is accomplished by the applied force. I have absolutely no background or training in physics whatsoever.
So…
Sam Axe
- 251
12
votes
9 answers
Is velocity real?
This sounds like a stupid question but I am do not grasp physics concepts easily. "Velocity" is just the change in displacement over the change in time. I can see displacement and time as intrinsically real, but I don't grasp velocity as having any…
SHOCK
- 129
12
votes
4 answers
If work is a scalar measurement, why do we sometimes represent it as the product of force (a vector) and distance (scalar)?
Consider an object being pushed 3/4 of the distance around a circular track. The work done on the object would be the distance of 3/4 the track’s circumference times the force applied to the object (given that it was pushed at a constant force).…
R_4127
- 167
10
votes
3 answers
What is displacement? Position relative to a reference point or change of position
What is the "official" or most useful definition of displacement in the context of kinematics?
There are two common ones:
Displacement is the length and direction of a line from a fixed reference point. (Basically position).
Displacement is the…
toksing
- 133
10
votes
4 answers
Does the displacement in the definition of work correspond to the displacement of the object or the point of application of the force?
Work is defined as
$$W = \vec{F}\cdot\vec{s}$$
But what what exactly is $\vec{s}$? Is it the displacement of the body on which the force is being applied? Or is it the displacement of the point of application of the force?
If you look at the…
Gerard
- 2,838
9
votes
2 answers
What is the origin of the naming convention for position functions?
In physics, position as a function of time is generally called $d(t)$ or $s(t)$. Using "$d$" is pretty intuitive, however I haven't been able to figure out why "$s$" is used as well. Is it possibly based on another language?
jli
- 191
9
votes
3 answers
Work = Force x Distance vs Displacement
The difference in using Distance vs Displacement is demonstrated in this example:
Work = Force x Distance
If I carry an object to and fro 10 metres, the work done would be Force x 20 metres.
and
Work = Force x Displacement
If I carry an object to…
George
- 193
8
votes
2 answers
Area under a displacement graph
If the area under an acceleration-time graph denotes velocity and the area under a velocity-time graph denotes displacement, what exactly does the area under a displacement-time graph denote?
Hele
- 183
8
votes
3 answers
What does the 'displacement' refer to in the definition of work?
The definition of work given in books is The work is said to be done by a force on a body, when the body is moved by the force through some 'displacement'.
Now let a body of mass $m$ at rest. When a force $F$ is applied on it, it gets accelerated…
Gurbir Singh
- 714
7
votes
2 answers
The physical meaning of electromagnetic waves
What, fundamentally, is an electromagnetic wave? As far as I know, all wave phenomena are derivations of an oscillating processes, e.g. particles vibrating in a medium. I can't imagine a wave process which couldn't be explained as moving particles:…
rook
- 245
7
votes
7 answers
What is the difference between position, displacement, and distance traveled?
Suppose the question is somewhat like this:
If $v=8-4t$ and the position at time $t= 0\ \rm s$ is $2\ \rm m$, find the distance traveled, displacement, and final position at $t=3\ \rm s$
Since $\text dx/\text dt=v=8-4t$, then…
Neville
- 75