Geometric object with magnitude (length) and direction.
-1
votes
1answer
1k views
how to calculate the angle in the x-y, y-z, x-z plane given only 3D vector direction and magnitude? [closed]
Please help me solve this. I have been thinking of all sorts of ways to solve this but can't figure out how :(. Ok here's the problem:
I am given a three dimensional velocity vector (i know the ...
5
votes
1answer
224 views
What does scalar phi represent in spacetime?
Trying to understand one-forms and vectors via Schutz's A First Course In General Relativity.
His example uses a spacetime diagram, a scalar field phi, a curve (worldline) parametrized using proper ...
-5
votes
1answer
206 views
What is a simple physics application of the reciprocal of a square root? [closed]
I learned yesterday that the inverse of square roots is used to calculate the vectors of surface normals in 3d graphics. It seems like such a mind-bogglingly simple idea, and it leads me to wonder if ...
2
votes
2answers
419 views
Nature of spacetime 4-vector and tangent space?
An entry level confusion about spacetime. I understand that a 4-vector describes a point or event in spacetime. But I've also read (Bertschinger, 1999) that re spacetime "we are discussing tangent ...
1
vote
1answer
1k views
The resultant of two forces acting at any angle?
I am studying about forces as vectors. And they give me this equation:
$c^2 = a^2 + b^2 - 2ab \cos C$
Can anybody explain me the second part of the equation? I perfectly understand $c^2 = a^2 + b^2$ ...
4
votes
1answer
1k views
Uniqueness of Helmholtz decomposition?
Helmholtz theorem states that given a smooth vector field $\pmb{H}$, there are a scalar field $\phi$ and a vector field $\pmb{G}$ such that
$$\pmb{H}=\pmb{\nabla} \phi +\pmb{\nabla} \times \pmb{G},$$
...
0
votes
3answers
671 views
Direction of Magnetic force from a current running through a coil of wire
What is the direction is the magnetic force vectors pointing from a coil of wire that has current running through it?
...
7
votes
6answers
807 views
Quaternions and 4-vectors
I recently realised that quaternions could be used to write intervals or norms of vectors in special relativity:
$(t,ix,jy,kz)^2 = t^2 + (ix)^2 + (jy)^2 + (kz)^2 = t^2 - x^2 - y^2 - z^2$
Is it ...
0
votes
2answers
251 views
vector cross products
Lets say you have a free particle in a rotating frame of reference with constant angular velocity $\mathbf{\omega}$. By free, I mean there are no real forces on it. Lets call the moving system ...
0
votes
2answers
392 views
Understanding weight on an inclined plane
I'm trying to solve a problem where I have an object resting on an inclined plane, with the angle of the plan being alpha, and the weight being w. I'm having trouble figuring out how I can calculate ...
0
votes
3answers
1k views
Vector product in 2 dimensions [closed]
If I have a vector A=4i+3j and B=5i-2j, how can I find the vector product AxB? I know that given the angle, its C=AB sin theta, but how can I solve this without the angle?
6
votes
3answers
1k views
Physics of a skateboard ollie
Does anyone have a good explanation of the physics and vectors of force involved in the skateboarding trick the ollie (where the skater jumps and causes the skateboard to rise off the ground with ...
1
vote
3answers
908 views
Can vectors in physics be represented by complex numbers and can they be divided? [closed]
Below is attached for reference, but the question is simply about whether vectors used in physics in a vector space can be represented by complex numbers and whether they can be divided.
In ...
2
votes
3answers
428 views
negative vectors (eg velocity)
If you said someone had a velocity of -12mph and they were traveling north? Wouldn't it mean that they were traveling 12mph south?
This is a quote from here:
if something [object-x] moving to the ...
8
votes
5answers
873 views
How is it that angular velocities are vectors, while rotations aren't?
Does anyone have an intuitive explanation of why this is the case?
