Velocity Definition and 1000 Threads

v=16m/s+4*.659s=18.636m/s (for lift) v0=16m/s-9.81*.659s=9.53m/s my question is that why 16m/s is considered for screw velocity ? it is given for lift .what does it mean 9.53m/s? If you drop something , it gets acceleration and I calculate it 6.45m for screw while falling and why should I...

A 0.1 kg arrow is moving at 48 m/s to the right and strike a 3 kg object (helmet resting on a 5 kg head) moving to the left towards the arrow at 9 m/s (full mounted charge). It takes 80 Joules to penetrate the 3 kg helmet, what is the velocity of the arrow after penetration when it slams into...

I uploaded the paper from Belden cable company. It said the velocity slows down to 5EE6 m/sec from 1EE8 m/sec at RF speed. I don't remember I ever read this before, I thought velocity = 1/sqrt( μ/ε). Please give me a link on the reason if this is true. Thanks Alan

Hello, there are a couple things about magnetism that I do not understand. 1. Why didn't we define the magnetic field to be in the directions of the force? This isn't really a technical question, I am just more curious about why it is this way. The way I was thinking of it, the math seems to...

Hello all, I have a question with the helix path of proton in a magnetic field that I am a bit stuck on. Question: Equations: F = qv X B F = mv^2/r d=vt My Attempt: Think the graph drawn is good enough for questions (a). However, I am stuck on (b) and (c). Firstly I am not entirely sure...

hi, my high school physics is letting me down here and I just have to get an explanation... when you talk to gun guys, they say that the maximum velocity that a bullet reaches is the muzzle velocity ... i.e. the absolute velocity of the bullet at the instant that it clears the...

I am in Algebra 2 and the homework asks a question: "You and a friend arw driving golf balls at a driving range. If the angle of elevation is 30 degrees and the ball travels 625 feet horizontally, what is the initial velocity of the ball?"

If the velocity gradient decomposition is done by symmetric and antisymmetric parts then ##\frac{\partial v^i}{\partial x^j}=\sigma_{ij}+\omega_{ij}## where ##\sigma _{ij}=\frac{1}{2}(\frac{\partial v^i}{\partial x^j}+\frac{\partial v^j}{\partial x^i})## and...

I am strugglin with this step in my assignment. I am dealing with a centrifuge with a known moment of inertia. I should write the expression for a torque of the motor and express it as a function of angular velocity. Can you help me please?

Homework Statement The graph shows the variation with time t of the acceleration a of an object (graph attached). What is the change in velocity of the object in the time interval 0 to 4s? Homework Equations a = v/t The Attempt at a Solution My initial answer was -8 m/s, by simply finding the...

Homework Statement The water in a river flows uniformly at a constant speed of 2.50 m/s between parallel banks 80.0 m apart. You are to deliver a package across the river, but you can swim only at 1.50 m/s. (c) If you choose to minimize the distance downstream that the river carries you, in...

Homework Statement A Doppler flow meter is used to measure the speed of red blood cells. The frequency of the apparatus is f = 12 MHz. The sensor in the apparatus measure 1.8 kHz beats between the emitted frequency and the frequency of the ultrasound reflected back by the blood cells. The speed...

Hello. I recently began this problem, but the site I'm working this problem on isn't showing me whether the answer is correct or not. Can someone please check my work and just verify that it's correct or state if it isn't and why? 1. Homework Statement A cosmic-ray photon (with mass m...

Homework Statement A proton moves through a uniform magnetic field given by B=(13.7i−22.9j+23.5k) mT. at time t1 v=(vxi +vyj+1.68k)km/s and the magnetic force is given by F= (4.22e-17i + 2.52e-17j). What are vx and vy Homework Equations F=q(v x B) The Attempt at a Solution First I converted...

Homework Statement Finding the general formula for max angular velocity ( answers say 0.839*(g/b)) but I do not understand how Homework Equations 0.839*(g/b) The Attempt at a Solution

we all know escape velocity is a velocity in which a body can escape orbit around the Earth and fly off into space. this needs to happen in space our just out of our atmosphere, due to drag that could bring an object back into orbit and cause it's velocity to degrade to a point where it would...

Homework Statement A photon with an initial wavelength of 0.1120 nm collides with a free electron that is initially at rest. After the collision the wavelength is 0.1140 nm . a) What is the kinetic energy of the electron after the collision? b) What is its speed? c) If the electron is...

I need to make an integral to fine the speed of the earth. Say the radius is 6378137 meters. How would I account for things closer to the axis that have a radius of 0.0001 meters? I don't think I can just take the speed at the radius. So I found that the Earth rotates at 6.963448857E-4 revs/min...

I'm trying to wrap my head around the dispersion relation ##\omega(k)##. I understand how you can construct a wavepacket by combining multiple traveling waves of different wavelengths. I can then calculate the phase and group velocities of this wavepacket: \begin{align*} v_p &=...

Is there a correlation between acceleration and velocity? If acceleration is rising will the velocity also rise?

This is a question about the concepts behind rigid body rotation when we use relative velocity. In general, let us say that we have a rigid body and on it are two points, A and B, which are moving with velocities vA and vB respectively. These velocities are in random directions. The theory...

think of a engine. it has a flywheel and a rod connected to it. a string had been totally wrapped around the rod and a mass is hanged from the very end of the rod. the system is in equilibrium. but as the engine starts to rotate, the rod with rotate as well and cause the hanged object to go...

There are galaxies that are so far away that metric expansion causes them to have a co-moving recessional velocity that exceeds the speed of light. However, those galaxies are also so far away that the time it took the light to reach us was itself billions of years in the passage of its journey...

Homework Statement Someone shot the bullet perpendicular to the ground. And there is air resistance. Velocity of bullet is v^2 = Ae^(-2kx)-g/k upward v^2 = g/k-Be^(2kx) downward A,B is constant, g is a gravitational acceleration, k = c2/m , c2 is a resistance constant, m is a mass...

$$V_{HE}=\sqrt{\frac{\mu}{a}}$$ What is the rationale for this formula when we can determine the change in velocity from Earth's orbit to transfer orbit using the vis-viva equation? Likewise, what is the use of defining the radius for the sphere of influence for interplanetary transfer...

1. A stone is thrown vertically downwards from the observation deck of the CN Tower, 400 m above the ground, with a velocity of 12 m/s [down]. A) How long will it take the stone to reach the ground ? B) How fast will it be going when it hits the ground ? I just got into physics, so I’m not...

We are all familiar with the concept of terminal velocity due to air friction in the direction towards the earth, but what about the other direction? Given enough applied force, is it possible to experience a terminal velocity upwards?

What do the average velocities on the very short time intervals [2,2.01] and [1.99,2] approximate? What relationship does this suggest exist between a velocity on an interval [a,b] and a velocity near t=a+b/2 for this type of polynomial?

Greetings, I am searching for an explanation that connects the mean squared displacement in an ensemble of particles to the velocity autocorrelation functions. I know that they are connected since both of them can be used to calculate the diffusion constant. But I do not find a mathematical...

Homework Statement A solid body begins to rotate around a fixed axis with angular acceleration ##\beta=\beta_0\cosφ##, where ##\beta_0## is a constant vector, ##φ##, is the angle of rotation of the body from initial position. Determine the angular velocity of this body as a function of the...

I have been reading up on the kinetic theory of gases, and I'm unsure whether I have correctly understood why particle velocities become correlated after colliding. Is it because during the collision they exchange momentum and thus their velocities (and hence trajectories) are altered in a...

Homework Statement Homework Equations Vy2 = Vyo2 + 2ayt y = 1/2(Vyo + Vy)t The Attempt at a Solution So I have "solved" this problem with both the equations above. Using the Vy2 equation I get the result of 32.83m/s. Using the other equation I get a result of zero, because Δy = (0 - 55) =...

Homework Statement Homework Equations v = I + j + k v = d/t The Attempt at a Solution I thought the answer was as simple as: v = 63i + 0j + 0k, since the car only has motion in one direction... ...but I got it wrong, so clearly I'm missing something here.

Homework Statement I am solving a kinematic problem, where I have a link that is attached to a rotational joint. I need to find the position of the joint for t=0..8, and I need to do it for every 0.01s. The problem comes from the fact that I have three stages for the velocity, during t = 0..0.1...

Homework Statement A 0.1 kg nut is thrown by a squirrel off of the top of a 10 m tall tree. It is thrown with an initial upward velocity of 4 m/s and an initial horizontal velocity of 3 m/s. a) How long till it reaches the top of its arc? b) From the top of its arc how long till it reaches the...

Hi! I have a question about escape velocity. If a planet is bigger and have a greater escape velocity than another planet. Do this effect the density of the bigger planet in any way? Or do we have to know the mass of the bigger planet to know if the density is larger or lower for this planet?

Two objects of the same shape (say balls) fall through the Earth's atmosphere. For simplification, let's say that the air density is the same (some average sea level value) despite altitude change. One ball has considerably bigger mass than the other, but besides that, they're the same. Will...

1)In a flowing fluid in laminar fashion we know that it flows in planes which slides over each other, Let's take a fluid element (cylindrical) in a pipe(Radius=R) the resistive force is (stress)(cross section area of cylinder with radius 'r') acting in backward direction, now if I take Flow...

Problem: Dr. L and his cat Kepler are coming home from fishing. They ended their trip on the south bank of a river, directly across a 1200 m wide river, from where Caroline was going to pick them up on the north bank. They are in identical boats that can travel at 4 m/s (Vb). The river is...

I apologize for the simplicity of the question. I have been reading a paper on the Legendre transform (https://arxiv.org/pdf/0806.1147.pdf), and I am not understanding a particular step in the discussion. In the paper, Equation 16, where ##\mathcal{H} = \sqrt{\vec{p}^2 + m^2} ##...

When a mass is in SHM, and is moving towards equilibrium point, its velocity starts to increase but why does acceleration decreases? What is the gradient when velocity is increasing and when it is at maximum? Thanks a lot!

if an objects terminal velocity in air is 18m/second, when what would be an equation that describes its velocity from t0?

I have a 1973 Ford 200" six to replace the same size engine in my 1965 Mustang. The .060" overbore in the original engine is too much making the walls too thin. It works but hard starting when hot, so I got a newer 200. The intake is cast with the head so the intake manifold can be a problem...

Homework Statement Two rubber pads are affixed at the bottom of a box and the assembly thus formed is placed on a uniform slope of inclination 0.5 degrees. Coeff of friction is 0.60 between the pads and the plane. Two electric motors installed in the box can make the pads move back and forth...

Homework Statement a particle's position is the vector r=(ct^2-2dt^3)i+(4ct^2-dt^3)j where c and d are positive constants. find the expression for the x-component of the velocity (for time t>0) when the particle is moving in the x-direction. you should express your answer in terms of variables...

I just confused about it.Why can't we discribe a particle just one wave function instead of wave packet(group of waves with different phase velocities)?

Homework Statement Homework Equations Bernoulli equation. Continuity equation The Attempt at a Solution Area of pipe is constant, so v_a = v_b = v_c = v_d.[/B] Using point on water surface and point D. Point on water surface: z = 8, v = 0, P = 0 (P_atm) Point D: z = -2, P = 0 (P_atm) v =...

Homework Statement I am having a bit of confusion regarding this: When you write dr/dt (rate of change of position vector with time, sorry I don't know how to use LATEX), do you mean instantaneous or average velocity? As we are considering a very small time interval, I guess it is...

Homework Statement A car moving at 20m/s starts decelerating, travels distance d, and stops. Find the car’s velocity at distance d/2. Homework EquationsThe Attempt at a Solution my brain is fried. I feel like I’m missing something obvious but I just don’t get it.

Homework Statement The transverse velocity of the particle in Sections 2.5 and 2.7 is contained in (2.77), since By taking the real and imaginary parts, find expressions for v_x and v_y separately. Based on these expressions describe the time dependence of the transverse velocity. Homework...