All Questions
24
questions
0
votes
1
answer
34
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Average angular velocity of a particle that retrogrades based on position of another
I originally thought that this problem would be trivial to solve, but it has proven more difficult than I expected.
Suppose there are two runners on a circular track with radius r. Runner a runs at a ...
0
votes
1
answer
71
views
Projectile Vectors Speed
At time $t = 0$, a projectile of mass $m$ is launched from the origin at an angle $α$ to the
horizontal with speed $U$.
Let the position vector of the projectile be $\mathbf{r} = x\mathbf{i}+z\mathbf{...
user1071088
2
votes
3
answers
1k
views
I don't fully understand why Pythagorean theorem works with velocity vectors.
I get why it works with displacement because that's what the theorem was originally meant for, lengths.... I find it harder to wrap my head around it when its velocity. If anyone has a good ...
1
vote
1
answer
33
views
What is the explicit expression of a plane wave in the frequency domain?
A plane wave in the time domain can be written (using notation for an electric field):
$$\boldsymbol{E}(\boldsymbol{r},t)=\boldsymbol{E}_0 e^{i(\boldsymbol{k} \boldsymbol{r}-\omega t)}$$
what is the ...
- 187
-1
votes
2
answers
418
views
Why is the direction of angle theta in circular motion towards and inwards?
Why is the direction of angle $\theta$ in circular motion towards and inwards of plane x-y axis?
I am not getting this concept at all.As the angel theta is changing ; the arc length (s in diagram ) is ...
- 742
1
vote
1
answer
260
views
How to get the necessary acceleration for a block to remain in place when pushed by a wedge?
The problem is as follows:
The figure from below represents a wedge which has a mass $M$ which is
being pushed by a force $F$. On the top of the wedge there is a small
block whose mass is $m$. Assume ...
- 4,185
0
votes
1
answer
126
views
To find a vector perpendicular to a vector with variable values
Let A vector = iA cos$\theta$ j + A sin$\theta$ be any vector. Another vector B which is normal to A is
How I solved it:
I thought that there can be two possibilities in which A vector is ...
user841124
0
votes
2
answers
79
views
How to find the acceleration of a cart sliding over a wire?
The problem is as follows:
The diagram from below shows a cart has a mass of $2\,kg$ is carrying
a solution of sucrose as ballast which has a mass of $6\,kg$. Below
the cart there is a brass sphere ...
- 4,185
0
votes
1
answer
35
views
How to find the modulus of the tension of a wire when a sphere is over a bar?
The problem is as follows:
The figure from below shows a system which is at equilibrium. The
sphere is frictionless, homogeneous and its mass is $5\,kg$. The
homogeneous bar has a mass of $10\,...
- 4,185
1
vote
2
answers
337
views
How to find the tension in a wire connecting three spheres?.
The problem is as follows:
The diagram from below shows three spheres identical in shape and weigh $6\,N$. The system is at static equilibrium. Find the tension in Newtons ($\,N$) of the wire ...
- 4,185
0
votes
2
answers
2k
views
How to find the tilted angle from a set of hanging masses between two pulleys?
The problem is as follows:
The figure from below shows three masses tied to a central one which
is hanging with respect of a floor. Find the angle so that the system
remains in static ...
- 4,185
0
votes
2
answers
71
views
The intersection of $w = x / \beta$ and a line parallel to $w = \beta x$.
If you are familiar with physics, you may have guessed what the background is… but, the following is simply a question of elementary geometry. (Not consider the special relativity.)
Question:
...
- 665
0
votes
1
answer
46
views
How to find a force when a pair is given in a diagram with an acceleration?
The problem is as follows:
A body of $5\,kg$ of mass is at rest when $x=0$. suddenly, two forces $\vec{F_{1}}$ and $\vec{F_{2}}$ act on the body applying on it an acceleration of $10\frac{m}{s^{2}}$ ...
- 4,185
1
vote
2
answers
778
views
How do I find the minimum force to be applied to a block sliding in a incline such as it moves with constant velocity?
The problem is as follows:
The figure shows a block over an incline. Find the minimum force that must be applied to the block so that the body of mass $m=2\,kg$ such as that body moves with constant ...
- 4,185
0
votes
0
answers
143
views
How can I find the horizontal contact force between two circles?
The problem is as follows:
The figure from below shows a rectangular object entirely flat which
is placed over two circles of radius $R$. The superficial mass density
of the object is $\sigma$ ...
- 4,185