Velocity Definition and 1000 Threads

First calculate mean velocity: 400 hl h-1 = 40,000 L / h-1 = 666.67 L/min 1L/min = 10^ -3 m3/min 666.67 L/min = 0.666 m3/min = 0.0111 m3/sec Cross sec area = (3.14)(0.1/2)^2 = 7.853 x 10^-3 m2 0.0111/7.853 x 10^-3 = 1.413 m/s Re = (1010)(1.413)(0.05)/0.0025 = 28,542.6 Am i right here? Re...

I want to clarfiy some ideas, so let us assume an inital observer measures a 4 velocity of an object. ##\vec{u} = (c\gamma_u, \gamma_uu^x, \gamma_uu^y, \gamma_uu^z)##. When we calculate the magnitude of the 4-velocity we get, $$\vec{u} \cdot \vec{u} = -c^2\gamma_u^2 + \gamma_u^2U^2$$ where...

Hey! :o A point is moving linearly with constant velocity $v$ and the movement is $x=a+vt$. The below information is given: Find the initial position $a$ and the velocity using the method of least square. Could you give me a hint how we use this method here? Couldn't we use the data of...

Please can I ask for help with the following as to where I'm going wrong. Book answer is 20 knots and 315 degrees My solution: In the below diagram I have sketched the two situations, k is the true speed of the wind. First question is, is my diagram correct? The velocity of the wind...

Hi I found this paper on the measurement of unknown velocity vector of a closed space. Does it mean that it is possible to measure the unknown velocity vector of a closed space ? Can someone explain it to me

The first thing I did, was to find the equations for player A (p) and ball's (b) path (for each i and j component I used the equation I wrote in the relevant equations) and then I found the derivative of both equations so I could have the velocity: $$\vec{r}_p(t)=(6t^2+3t)\hat{i}+20\hat{j}...

I was told to solve the second equation above for x to get l2 and l2, but that only gets me those in terms of other unknowns. I'm assuming I just need to solve t for my knowns, but I keep getting caught up by my unknowns. i.e., solving for x gives x = (l2*L*v2)/(l1*v1+l2*v2). Please note "l" is...

Greetings, how do - the velocity distribution of the solar wind at 1 AU - the velocity distribution of the solar wind in our line of sight look like? I have found the 400 Km/sec but no further information. Is it an average values? Is this radially on the sun the same? Links with graphs are...

What is the kinetic energy equal to during the escape velocity? Henceforth, what is exactly happening at the escape velocity in terms of gravity?

Hi guys I saw that equation of the velocity of electrons In a periodic potential $$ v = (1/h) grad E(k) $$ in my textbook we use in our solid state physics course without any proof or any thing and when I searched for it I found that its derived in Ashcroft book appendix E : Is there is any...

So thing that confusses me, is what is the difference regarding the calculation of speed and velocity? In think I should use the formula I wrote above to find the average velocity, but I don't understand what the formula for average speed will be then. By the way, when using the formula above...

The force on a test charge Q due to source charge q, depends on both their velocities in addition to several other quantities. For electrostatics, the source charge is at rest (its velocity is zero) but the test charge may be moving. Then how does Coulomb's Law accommodate for this velocity of...

Here it is given that the flag flutters in the direction of wind w.r.t. to man. But why would the direction of fluttering of flag would change without any tangential acceleration. Is there a pseudo force acting on it. I think the direction if fluttering should remain same.

Since initally the rocket at rest I wrote $$\vec{p}^R_i = (m_0, 0,0,0)$$ and at final situation $$\vec{p}^R_f = [m_0-\varepsilon m_0 N](\gamma, v\gamma, 0 ,0)$$ $$\vec{p}^F_f = [\varepsilon m_0 N](\gamma', -u\gamma', 0 ,0)$$ After equating them I get $$1 = \gamma - \varepsilon N\gamma +...

Let´s suppose we are observing the sun and measuring some spectral lines. Does the velocity correction´s formula for the Earth include the rotational velocity components of the Sun as well? or rather are we basically measuring both velocity contributes of Earth and of Sun together (receeding...

In a previous thread it was concluded that both torque and angular momentum are taken about a chosen origin, and these quantities are generally not invariant under translations of the origin (since ##\vec{r}## changes but ##\vec{v}## does not, etc.). The moment of inertia tensor doesn't...

The magnet being used % magnet dimensions [m] d = .0127; r = .00238; %mass of magnet [kg] m_w = .0017; % other constants u_0 = 1.26E-6; % permeability of free space constant T m/A g = 9.81; % gravitational constant in/s^2 %coil properties [22 gauge wire] [m] a = .00635; %radius w =...

Summary:: not constant spin How could I calculate the system lagrangian in function of the generalised coordinates and the conserved quantities associated to the system symmetries? I've been struggling for the case with not constant angular velocity, but I don't realize what I have to do...

I keep getting into these discussions and finding out they are not as simple as I thought. Or at least, my math is rusty. Scenario A: Two ships are each receding from Earth at .9c in opposite directions. Since these are velocities, they should have opposite signs. That can't be right, since...

for example take a look on this graph

So here is my problem I have had a go at this and get an answer of 8.34cm to be my final amplitude The next part that I have been given is to calculate the velocity of when 2 waves are added together. I'm not so sure how to go about this, this is what I have tried anyway Can someone...

A known force is doubling (egal) over a known distance, accelerating a mass. How do I calculate the final velocity of the mass at the end of the known distance , when the mass has doubled? I don't know the time. The mass is accelerated from 0 meter and from 0 velocity.

So the way I have gone about it is to assume that the equilibrium position is half way between the 2 end points, hence the amplitude of this motion is 9.3/2 = 4.65 cm Therefore the displacement of the particle when it is 2cm away from one end point should be the distance between that point and...

Hi there ... How do I calculate the change of angular velocity, when demonstrating conservation of angular momentum? I mean the change of angular velocity depends on the ratio between the two (rotating) masses that moves a distance along radius, and the (rotating) mass of the system itself. In...

I have a simple Fortran code for solving velocity and displacement of spring, the code works fine when writing all together without using a subroutine. but as I am learning Fortran I tried to do it using subroutine, but I keep getting errors appreciate any help in advance. program msd implicit...

I'm thinking some of the kinetic energy and momentum from the lighter cart transferred to the heavier.

I tried resolving the information given into vertical and horizontal components. I then tried to find time, as this is how I would find the initial velocity. However, I am unsure of how to use the angle in this problem to help solve it. I am also unsure of how to find the initial velocity only...

any tip to start?

After noting w=vk and differentiating with respect to k, and lots of simplifying, I get: Vg = c/n +(2*pi*0.6)/(k*n) This doesn't correspond to any numerical value though...

x

I chose coordinates where down is positive. So the force going up is $$F_{up} = mg - cv^2$$ $$a = g + \frac{c}{m}v^2$$ $$a = g + \frac{c}{m}v^2$$ $$a = g \left(1 + \frac{v^2}{v_t^2}\right)$$ $$a = \frac{dv}{dt} = v\frac{dv}{dy} = g \left(1 + \frac{v^2}{v_t^2}\right)$$ I used normal separation of...

I was not really sure as to whether to ask this question here or the h/w forum as its something I am personally trying to understand. However, I shall let the admin decided. The question comes from a book called : . The specific question I have an issue with is not the question itself but the...

I could use some help with this problem. I am having trouble finding how to change the dependence from velocity to time in a).

Wikipedia gives, "The relative velocity ##{\displaystyle {\vec {v}}_{B\mid A}}## is the velocity of an object or observer B in the rest frame of another object or observer A." Suppose the coordinate system being used in the rest frame of ##A## is has its origin slightly displaced from ##A##...

Hi there, I'm very stuck on this problem when approaching it like this. I know I could use the Landau Criterion for rotons but that's not accepted here, it wants the approach to come from the uncertainty principle. My thinking is along these lines: There will be a change in chemical potential...

As ##P=ccte## we can find final velocity considering a plastic collision ##m_0 . v_0 =(2m+m_0).V## But what about the angular velocity? Because, as the bullet hits the centre of mass of the string, it won't have angular velocity

Just wanted to check in my workings to see if they are correct (seemed to be too short to me?) Since electrical conductivity is 820 (ohm.m) which is = n*e*(mobility) Mobility =0.17083? And I can simply get drift velocity by multiplying mobility with an electric field (600V/m)? Cheers

(pw is person to water, pf is person to ferry, fw is ferry to water) I get Vpw = Vpf + Vfw. Therefore Vfw = Vpw + Vpf, which is Vfw = -Vwp + Vpf. I also have that the x component of Vpw is negative. I think I'm getting confused with either the order of the formula or the negative negatives (or...

I calculated the system's change in gravitational potential energy through the equation k=mgh. I used this equation twice, once for the 3.5 kg block with k =(3.5)(9.8)(-0.54) and once for the 1.0kg block, k = (9.8)(1.0). I got -18.522J & 5.292. Is the change just -18.522 - 5.292 J...

From Ball 1 I can can determine it's initial velocity and then maximum height. I'm not sure how this is relevant, as I cannot find a formula using angle, time, height and velocity. I have found h=V(squared) x sin (squared) Theta / 2g and also t=2Vsin Theta/g. These give similar, but different...

In the picture, there is a problem where the t is in units of square root(l/g), and V in square root(gl) I am wondering 1. What it means when time is in units other than time? Does it mean that when solving I have to take time/squareroot(l/g) 2. How did they get square root(l/g). Thank you...

Summary:: This is a question about finding the acceleration of a point in a mechanism Hi, I have a question about the mechanism shown in the attached picture: Question: We are told that \omega = 6 rad/s and the first part is asking me to find the acceleration of point P on the piston when...

I solved a and b fine, I just don't know where to start c a) i=Ft i=change in p and p=mv so i=90=45v so v=2m/s b) same thing just using the other mass i=90=70v so v=1.3m/s c) v=d/t so 1.3=d/1.5 but that would be d=1.95 and the answer key says d=.96m

I am working on simulating the movement of small spherical objects under the influence of drag and a number of other forces that, at least for now, don't depend on the object's velocity. Normally I would sum up all these forces, including drag, to ##F_\Sigma## and update the object's speed...

Is an object with escape velocity in gravitational freefall?

Could someone please help me see where I am going wrong here? During a race between two boats A and B there is a wind of 18 km/h blowing from due north. The resultant velocity if A is 12 km/h on a bearing of 060. Find the direction of the wind relative to A. My reasoning: (Relative to the...

I believe they are the same?I think i am wrong.

As I have shown in the picture even if their is minimal change but shouldn't it increase after a long time as minimal changes will keep accumulating.