All Questions
66
questions
0
votes
5
answers
125
views
Direction of impulse
My textbook has the following problem:
A batsman deflects a ball by an angle of 45° without changing the initial speed which is equal to 54 km/h. What is the impulse imparted to the ball? (Mass of ...
- 342
1
vote
0
answers
25
views
Question about how force is distributed based on initial hitting angle in multiple pool balls
Suppose you have a standard triangle rack of billiard balls under ideal conditions (all balls are touching and identical, no friction, and all elastic collisions, ect). Suppose force F is applied to ...
- 11
0
votes
1
answer
173
views
Can momentum exist in a null direction?
CONTEXT (skip to "my question is"):
As I understand it, and correct me if I'm wrong, an orbit trades momentum between the X and Y directions. But spacetime can have negative and even null ...
- 278
8
votes
4
answers
1k
views
Why "time part" represents energy in Four-momentum?
I was going through Spacetime Physics by Taylor and Wheeler and came to a point where they said, and I quote,
In what follows we find that momenergy is indeed a four-dimensional
arrow in spacetime, ...
- 121
1
vote
0
answers
86
views
An object which was initially at rest explodes in three pieces. Is it necessary that all the pieces will be in same plane and not in 3 dimensions? [closed]
I found this question in a test paper and the answer was all the three pieces must be in same plane because three vectors must be in same plane to cancel each other but if we consider a case like this-...
- 11
1
vote
0
answers
73
views
Can vector operators in quantum mechanics be viewed as the components of some object?
The title pretty much says it all. For example, we sometimes think of the three momentum operators as components of a "vector operator" $\hat{ \vec{p}}=(\hat p_x,\hat p_y,\hat p_z)$. The ...
- 3,407
1
vote
1
answer
69
views
Direction of momentum in a collision
In a simple perfectly elastic collision 1-D collision, with a ball of mass M_1 striking a rigid wall of mass M_2 head on,also$$M_2>>M_1,$$
then by law of conservation of momentum. $$\Delta\vec{...
- 561
1
vote
1
answer
87
views
Origin of SR Energy and 4-momentum Norm
I've just started reading Sean M. Carroll's "Introduction to General Relativity: Spacetime and Geometry," and I've gotten hung up on the following after wading through the preliminaries on ...
- 255
0
votes
0
answers
88
views
Unpacking integrals in QFT and their notation
In a standard QFT course integrals are often written $$\int d^4pf(p)=\int dp^0\int dp^1\int dp^2 \int dp^3f(p^0,p^1,p^2,p^3).$$ This is just the standard notation for packing in a lot of math into a ...
- 385
0
votes
1
answer
135
views
Regarding linear momentum operator as vector operator
The vector operator $\hat V$ are defined as the vectors which satisfies the commutator,
$$[\hat L_i,\hat V_j]=i\hbar\epsilon_{ijk}\hat V_k.$$
$\hat L$ is the angular momentum operator.
Thus, if the ...
- 293
0
votes
1
answer
139
views
Convert 3-momentum vectors to spherical coordinate system [closed]
I have the 3 momentum vectors $(P_x, P_y, P_z)$ describing the position of a particle and I have to convert these coordinates to the corresponding spherical ones $(\varphi, \theta, r)$.
The equations ...
- 3
0
votes
2
answers
522
views
Is momentum along the line of collision conserved when a ball falls on an inclined plane
A ball of mass 1kg falling vertically with a velocity2m/s strikes a wedge of mass 2kg. ...
- 135
0
votes
3
answers
183
views
How should a character´s movement change after colliding with a wall? [closed]
This character is supposed to move in a straight line in any direction. Logically, it would mantain some momemtum and redirect its movement after colliding. Here is an elastic collision, where AB is a ...
- 3
1
vote
0
answers
93
views
About change $\Delta t$ to proper time for the the relativitistic momentum
The problem that we use $p=mv$ in all frames will cause the momentum is not conserved in all frames, and in my book, it is said that since $p=m\frac{\Delta x}{\Delta t}$, this $\Delta t$ causes the ...
- 125
1
vote
1
answer
469
views
Is momentum separately conserved in each axis?
For a projectile launched from ground, am I correct in saying momentum is conserved in the $x$ direction because no forces act in the $x$ direction (ignoring air resistance), but momentum is not ...
- 372