Velocity Definition and 1000 Threads

none

Let’s assume a world where it is secretly revealed that traveling West to East there is speed of light instantaneous, and in the reverse direction a c/2 velocity . Now let’s assume this applies to an arbitrary point in space and east and west assume are linear flat Now …. Let’s assume there’s...

There is a cylinder which is held by a rope, inside a pipe. Fluid is flowing (laminar) in the direction of Q. I'm trying to calculate the velocity profile in the gaps between the pipe and cylinder, using Navier Stokes. First question is, if ##\frac{R_1-R}{R_1}<<1##, which means the gap width is...

Hello! I have photon clock that moves to right side with velocity V. In the first case events A and B are depicted on the picture on the top side: In accordance with the Principle of Relativity I obtained second case. But I can't mark event B in the second case on the bottom side. Where...

What does this formula mean ? I can't find it anywhere. Vmax=Wmax x L. And Wmax=Wθmax. It came up in the pendulum chapter. L is string length.

I calculated part a of the question and I found the correct solution, which was 4.4m/s N35degE, but I don't understand how to find Tessa's velocity relative to the ground in part b using her velocity relative to the water which I found in part a.

If an electric charge q is moving with a certain velocity v and we want to slow it down, this can only be done with an electrical force because magnetic force is perpendicular to displacement, correct? (watch video, time stamp 0:42) video

From Khan Academy; “As truck moves with constant velocity down the road, its acceleration is zero. Therefore, the net force acting on the box must be zero.” Which forces are involved in a truck moving with constant velocity (and therefore no acceleration)? The gravitational force and the...

I calculated the average speed (100/5=20) and assumed that the speed at 100 m would be double that (20*2=40), since the speed starts at zero. Then i used the formula for acceleration with time and velocity (a = (vf − vi) / Δt) and got the following answer: a=(40-0)/5=8 m/s/s. This answer makes...

We know $$\vec{v}_{B/O} \equiv \vec{v}_{B/1}$$ $$v_{O/F} = v\hat{e}_t$$ $$a_{O/F} = \dot{v}\hat{e}_t + \frac{v^2}{R} \hat{e}_n$$\$$\omega_{1/F} = -\omega \hat{j}$$ $$\omega_{2/1} = \dot{\theta} \hat{i}$$Using velocity transfer relations, $$v_{B/F} = v_{B/1} + v_{O/F} + \omega_{1/F} \times OB$$...

With the given information , we can find ##y=h\cos\frac{\pi x}{L}## Since , the wheel has constant velocity ##v## , we can write the $$\vec{a}=0\hat{e_t}+\frac{v^2}{\rho+r}\hat{e_n}$$ where $$\rho=\frac{\left[1+\frac{h^2 \pi^2}{L^2}\sin\frac{\pi x}{L}^2\right]^{\frac{3}{2}}}{\mid...

I feel very dumb asking this question, but I can’t seem to find anyone else asking it. I understand geometrically how we get to: ##v = r * \omega## Where v is the tangential velocity, r is displacement (meters), and omega is angular velocity (radians/s). Isn’t this then m*rad/s? How do we get...

Does the v with the arrow underneath stand for velocity vector? If so, does the length of the arrow indicate the magnitude of the velocity? Is arrow length usually specific (x cm, or y mm, or whatever, indicating a specific magnitude, sometimes to scale)? Or is it usually relative (longer or...

Why can't I simply integrate a(x)=m*x with respect to x to determine the speed of a particle as a function of position v(x)=1/2*m*x^2+A?

As your velocity increases time in your frame of reference slows down with respect to other frames of reference until, at the speed of light, time essentially stands still. Hypothetically, I am travelling at the speed of light and, therefore, for me, time stands still. I am travelling to a star...

The answer is (C), but in my opinion all options are wrong: (A) is wrong because at X and Y the net force is maximum, not zero (B) is wrong because the direction of net force can be in opposite direction to velocity (C) is wrong because at the middle (equilibrium point) the acceleration is zero...

I thought velocity was always a vector quantity, one with both magnitude and direction. When it came to the suvat equations, where v = final velocity, and u = initial velocity, I thought both of those were vector quantities, e.g; v (final velocity) 112km/hr North u (initial velocity) 0km/hr...

We have 2+1 spacetime (x,y,t) and objects a) and b). The velocity of the object a) is greater than the velocity of the object b), so, according to special theory of relativity the time passes for the object a) slower than for object b) (t_2 is greater than t_1). So is the pinned picture correct...

A question states that a ball with a mass of 5 kg and a velocity of 10 m/s collides with a stationary wall. The question then asks for the momentum of the ball after the collision. No other information is given. This is a rather ambiguous question, as it doesn't provide the time taken for the...

We can determine the earth’s movement in relation to other astronomical objects, but we have no idea of our absolute movement, correct? The earth is spinning and revolving around the sun which is revolving around a galaxy that is expanding from other galaxies in the universe. The entire...

After a year of thinking about instantaneous velocity. I think that this notion is no more than a mathematic coincidence when mathematician tried to find the tangent of curve. The only definition of velocity that make sense is ##\frac{\Delta x}{\Delta t}##, this proportion is a quantity that...

Included a diagram as well... forgive me... I cannot seem to 'uninvert' the attached picture final velocity is zero if we set the lowest point that the mass reaches as zero, then the final height is zero let H be the 'extra' length that the spring reaches over and above the initial stretch...

When a car is moving the velocity of the connection point between the car and the ground is zero. So static friction must be act here ,mustn't it ? But my mentor said ,it is kinetic friction. Which is correct? If kinetic friction, why?

I'm trying to understand if I'm making a mistake because the answer in the textbook is ##10.2~km/s##. Here's my attempt at a solution: The subscript A is intended to mean apogee and P is for perigee. ##v_A = 3~km/s## ##w_A = \frac{v_A}{r_A} = 7.5 \times 10^{-5}~rad/s## ##L_i=L_f## ##I_Aw_A...

I apologize if this is a stupid question but how come we can't just say that for part (a) v_A = -v_1 j hat, and for (b) v_A=v2 sintheta i hat + (-v1-v2cos theta) j hat? i.e. how come we can't just do vector decomposition "normally"? I am especially confused about the given solution in (a) where...

The answer given is -10m/s2 because of constant downwards acceleration of gravity. i would like to know why is it not 0 at its peak height. at the top, velocity is momentarily 0, since acceleration is the change in velocity, change in 0 = 0. so why issn't a = 0? thanks

I get the impression that momentum, in most physics questions (at least at GCSE level), is instantaneous. Is that correct? I tried to apply the basics to a walk to the local shops that I take regularly Distance 0.9 miles Time taken 0.25 hours Avg S=D/T Avg S=0.9/0.25 Avg S=3.6mph Avg...

For reference I'm a high school senior in physics. My thought process: 1) If the force of friction and applied force are equal the object "should" be at rest because the forces are equal (obviously this isn't correct because my professor tried explaining it and I'm not understanding the...

no clues

First I tried to convert V = 61 rev/min to linear velocity. frequency = 61 rev / 60 sec = 1.017 rev/sec time = 1/f = 0.983 s V = 2(pi)r/t = 0.52*pi/0.983= 1.662 m/s From there I tried to find the maximum radius the coin could be at by using mu(v^2/r)=g r = mu(v^2)/g r= 0.47(2.76)/9.8 r= 0.13 m...

For a spherical body mass M and radius r, the escape velocity at the surface is ##\sqrt{\frac{2GM}{r}}##. At the surface, an object mass m has GPE ##-\frac{GMm}{r}## and 0 GPE at infinity. So ##\frac{GMm}{r}## KE must be converted to GPE which means the minimum take off speed must be...

As a child, one of my family friends was an 80 year old neighbor, Harry R. Caldwell, who had been a famous tiger hunter in his youth. He killed tigers and Kodiak bears with a .22 or .25 caliber high power load that some felt too small for big game. [edit: the claim about the bear is false...

I was taught to solve this problem by first finding the velocity of the body (of mass ##m ##) relative to the block of mass ##M ##. One way of doing this is as follows: first write $$ {v _{m _{B }}}^{2 }={v _{mx _{B }}}^{2 }+{v _{my }}^{2 } (I)...

Attempt is attached, thanks for the help :)

Hi, I have two topics: 1) Suppose a propeller is spinning very fast (say it's in a vacuum, no drag) and we arbitrarily lengthen its blades. Eventually the velocity of the tips of the propeller will approach the speed of light. That should be a speed limit, but that implies that the blades of...

## a_t = r\alpha ## ## 9.8 \: m/s^2 = (.25 \: m)\alpha ## ## \alpha = 39.2 \: rad/s^2 ## Since the cylinder rotates through 20.01 radians after 5 m of cord has been removed: ## \omega_f^2 = \omega_0^2 + 2\alpha(\Delta\theta) ## ## \omega_f^2 = 2(39.2 \: rad/s^2)(20.01 \: rad) ## ## \omega_f...

Using equation, Vm=(Vo+Vi)/2; 2= (4+Vi)/2 =>Vi=0. I.e, image velocity is zero. I can't understand how it is possible that the image is at rest wrt ground. If the object moves with more velocity than the mirror, wouldn't it collide with the mirror at some point? And plus the object is moving 2m/s...

Lets just say for the sake of argument that the earth, sun, solar system, galaxy were all moving due north at 1,000,000 miles an hour. If you were to travel due south at 1,000,000 mph you would basically be not moving at all. How would this affect time for you or anyone observing you?

I would like to discuss a few ways to apply derivatives in physics (I don't understand it fully). I don't need a full solution, I only need to understand how to successfully apply the derivatives First example, Thin insulating ring of mass M, uniformly charged by charge ##+q## has a small cut...

According to the problem statement: $$a = \frac{dv}{dt} = const \implies dt = \frac{dv}{a} \implies \int_{0}^{T} \,dt = \frac{1}{a} \int_{0}^{v_f} \,dv \implies T = \frac{v_f}{a}$$ Now, the distance covered is given by, $$L = \int_{0}^{T} v \,dt \implies L = \frac{1}{a} \int_{0}^{v_f} v \,dv...

[FONT=times new roman]Attempt : [FONT=times new roman]Let me copy and paste the question from the text alongside. [FONT=times new roman]Method 1 : [FONT=times new roman]I draw an image of the problem situation to the right. Boat B moves to the right pulled by a rope from the point O where...

At 3m: U = 3 x 9.8 x 80 = 2352J U at 6m = 6 x 9.8 x 80 = 4704J k = 1/2mv^2 (4704-2352)J = 1/2 (80) v^2 v = 7.67 m/s At 0m (bottom): U = 0 4704J = 1/2 (80) v^2 = 10.84 m/s Okay so what is bothering me here is just that my working doesn't take into account the...

I'm only confused about one part of this problem and that is setting up the conservation of energy equation. In the solution, they just wrote this: $$\frac{mv_o^2}{2} = - k \frac{q_1 q}{r} + k \frac{q_2 q}{l + r}$$ where ##r## represents the distance at which the force created by the negative...

I used law of conservation of energy to calculate (d theta/ dt)^2 (from:mgasin theta=1/2m(d theta/dt.a)^2+1/2mu^2(u is the velocity of the C ring at time=t)), but wasnt able to find u(velocity of C).Is there any relationship between the tangential velocity of B(d theta/dt.a) and velocity of C(u)...

I find the velocity vector that is perpendicular to the radius which is v*cos(theta). Once I obtained the velocity that is perpendicular to the radius I used the equation : v = wr. But my answer seems to be wrong, the actual answer to this question is v = wr*cos(theta). Why?

I've done internet searches on this. There doesn't seem to be any agreement. Is the direction of the drift velocity in a wire the same as the (conventional) current? [AI Chatbot reference deleted by the Mentors]

Einstein's theories are accepted since 100+ years. Modern science built on it somehow provides a proof of truth of his theories but what if one is living when Einstein proposed his theories and debating its merit? Einstein did two things: 1. He declared velocity of light as invariant c for all...

In figure AO = OB = 4m. C is the midpoint of AO. The rod rotates with a velocity of 5 rad/s about the axis PQ. What will be the rotational velocity of the remaining rod if AC part is suddenly dropped from the rod? Assume that the mass of this uniform rod is M.