All Questions
77
questions
0
votes
0
answers
20
views
How can we find the angle between areal vector and magnetic field?
For finding torque we need to find the angle between areal vector and magnetic field. But areal vector makes an angle 37° with the x axis and that means it makes 53° with magnetic field because that's ...
- 91
0
votes
2
answers
93
views
In equation of torque and angular momentum what is the position vector exactly
In terms of vectors:
$$
L = r \times p
$$
and torque:
$$
T = r \times F
$$
In both these cases what exactly does the $r$ vector represent? Is it vector from origin of axis or center of mass? How would ...
- 35
0
votes
3
answers
95
views
Convention or reality?
In case of a disc rotating about an axis perpendicular to its plane passing through its centre of mass, the torque vector points up or down depending upon direction of rotation. Is it just convention, ...
- 127
1
vote
1
answer
157
views
When do we use dot product and when do we use cross product? [closed]
I actually dont understand that when do we use cross product and when to use dot product ……it is very difficult to remember that a torque is cross product and work done is dot product. please tell me ...
- 179
1
vote
0
answers
75
views
How do I translate force in one point to another point in an object? [closed]
For a project I need to model a system where a body can pivot at one point, and is lifted up by a piston, to rotate the body around the point.
I am having trouble finding the formulas and ways to ...
3
votes
1
answer
151
views
Is the position vector an axial vector?
The displacement vector $\vec{r}_{ij} = \vec{r}_j - \vec{r}_i$ is of course a polar vector because it's completely independent of the choice of origin, but what about the position $\vec{r}$ which, by ...
- 35
0
votes
1
answer
131
views
Is there a serious ambiguity in the definition of the cross-product of unit vectors?
Consider a force F acting along the x-axis applied to a directed lever arm L parallel the y-axis, and with the conventional torque T parallel to the z-axis, with the three vectors a right-handed triad....
2
votes
2
answers
128
views
Why is the cross product used in torque? [duplicate]
Why is the cross product used in torque $$t = r\times F ~?$$
I know that the torque is the rate of change of angular momentum and angular momentum is defined as the cross product $$L = r\times P$$ ...
1
vote
3
answers
203
views
What illustrative example of the central axis theorm exists? This is not the parallel axis theorem
This is from Ira Freeman's translation of Georg Joos's Theoretical
Physics. I've taken a few liberties with the notation.
It may be shown also that there is always an axis such that if any point ...
- 2,015
1
vote
1
answer
79
views
Doubt regarding some overlooked steps when arriving at torque, in terms of Newtonian mechanics
The treatment of torque in most undergraduate introductory mechanics textbooks or pre-college textbooks assumes many things and doesn't explicitly state its assumptions. Torque is one such example. I ...
- 702
1
vote
3
answers
606
views
Is torque possible without any pivot point?
In the picture, AB is a rod. The resultant of force P=10N and Q=5N works at point C which is P+Q. When I apply both forces simultaneously, the rod will rotate and accelerate. 5N from both end will ...
1
vote
2
answers
85
views
How to draw vectors?
The images show rotational motion.Here, $r$ is the position of the particle and $F$ is the force applied on it.
Now, if I draw vectors $F_x$ and $F_y$ according to fig.2, I understand why it moves in ...
- 13
0
votes
1
answer
31
views
What specifically about the torque vector is perpendicular? Is the torque vector like this only so that it works smoothly with linear algebra?
What specifically about the torque vector is perpendicular?
Is the torque vector like this only so that it works smoothly with linear algebra?
The only explanation I get usually is "because it's ...
-1
votes
1
answer
36
views
Are these two torques identical? [closed]
Hello,
I had this question in a MCQ. According to the solution, these torques are indeed identical but I don't understand how.
I tried to decompose $\overrightarrow{AB}$ into $\overrightarrow{AC} + \...
- 13
1
vote
5
answers
1k
views
Differece between torque $\tau$ and angular velocity $\omega$
The title is a weird question, i know. But hear me out: Take the equation that relates the tangential velocity $\vec v$ and the angular velocity $\vec \omega$ of an object moving on a circle with ...
- 65