The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of an object's speed and direction of motion (e.g. 60 km/h to the north). Velocity is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of bodies.
Velocity is a physical vector quantity; both magnitude and direction are needed to define it. The scalar absolute value (magnitude) of velocity is called speed, being a coherent derived unit whose quantity is measured in the SI (metric system) as metres per second (m/s or m⋅s−1). For example, "5 metres per second" is a scalar, whereas "5 metres per second east" is a vector. If there is a change in speed, direction or both, then the object has a changing velocity and is said to be undergoing an acceleration.
Hi, if the velocity ratio is equal to the distance traveled by the effort divided by the distance traveled by the load, in a gears and wheels system, do you invert that in the case or gears? Making it number of teeth on driven gear divided by number of teeth on driving gear? Thanks
Homework Statement
A man let a stone from height 49 metres. After 1 second he threw a second stone. Both stones fell on same time. What is the velocity of second stone?
Homework Equations
h=1/2gt^2
h=1/2a(t-1)^2
The Attempt at a Solution
So I assume that if he let the first stone then the...
Hi everyone, I would like to know the formula for calculation of velocity and shear rate in my rectangular fluid channel.
Here are the important values regarding my rectangular channel. W= 2.5 mm, H=3 mm, L=35 mm.
Fluid: Diluted Bacterial suspension derived from wastewater.
Flow rate: 0.125...
Homework Statement
So I am given a problem where I am asked to find the time it takes to change the velocity of an asteroid by 1m/s. In a previous section of the problem I was asked to find the force through which the asteroid is being propelled, which I calculated it to be F=1.3x10^4 N, and...
Generalized momentum is covariant while velocity is contravariant in coordinate transformation on configuration space, thus they are defined in the tangent bundle and cotangent bundle respectively.
Question: Is that means the momentum is a linear functional of velocity? If so, the way to...
Homework Statement
Is it possible for the instantaneous velocity of an object at some time, t1, to not be parallel to the average velocity over a short time interval, Δt=t2-t1? If it is not possible, explain why not. If it is possible, explain what this situation implies about the motion of...
Hello,
I am in need of some clarification on tangential velocity in polar coordinates. As far as I know, the tangential velocity vector is ##\vec{v} = v\vec{e_t}##, where ##\vec{e_t} = \frac{\vec{v}}{v}##. This gives us the ##\vec{e_r}## and ##\vec{e_\varphi}## coordinates of the tangential...
Homework Statement
A drunken driver crashes his car into a parked car that has its brakes set. The two cars move off together (perfectly inelastic collision) for 6.0 m.
If the mass of the moving car is 1030 kg and the mass of the parked car is 1410 kg how fast was the first car traveling when...
Homework Statement
I am reading through Griffiths' Electrodynamics, and I have come to the scenario in the Relativity chapter where in an inertial reference frame ##S##, we have a wire, with positive charges (linear density ##\lambda##) moving to the right at speed ##v##, and negative charges...
Homework Statement
A 4-kg block moving at 7m/s makes a head-on collision with a stationary block of mass 3kg. Find the velocities of the two blocks after the collision.
m1=4kg, vi1=7m/s
m2=3kg, vi2 = 0m/s
Trying to find vf1 and vf2
2. Homework Equations
Using the conservation of momentum...
Homework Statement
Fission, the process that supplies energy in nuclear power plants, occurs when a heavy nucleus is split into two medium-sized nuclei. One such reaction occurs when a neutron colliding with a 235U (uranium) nucleus splits that nucleus into a 141Ba (barium) nucleus and a 92Kr...
Homework Statement
An archer launches an arrow from coordinates ##(0, 0)## at an angle ##\alpha## and with an initial velocity ##v_0##. There's a target located ahead of the archer and the center of that target is at coordinates ##(d, h)##. At what ##v_0## and at what angle ##\alpha## does...
Hey! I am new on the forum and I joined because I really enjoy physics but I have a horrible teacher. I was wondering if anyone could help me on a question
how do I find the velocity at the end of the zipline?
how do I find the momentum of the object going down the zipline after it is...
Homework Statement
(Translating from a Polish high school textbook, so if anything is unclear please let me know).
An object moves on a trajectory described by the parabola ##y=\frac{1}{2\lambda}x^2## such that the ##x## component of its velocity is constant and equal to ##v_0##. The...
Hey there,
If body 1, mass M1 has escape velocity V_e1 = (2GM1/r)**.5 but M2 is more massive than M1 is this relation still valid? In this case, the subordinate body really isn't the subordinate body so does this still hold? And r (distance b/t the two) changes not only due to the motion of M2...
Homework Statement
Acceleration is defined as the second derivative of position with respect to time: a = d2x/dt2. Integrate this equation with respect to time to show that position can be expressed as x(t) = 0.5at2+v0t+x0, where v0 and x0 are the initial position and velocity (i.e., the...
Hi
here is the situation; There's a spherical particle contained with a MEMS sensor (3D accelerometer and gyroscope) moving down a bed. What we want is to estimate the total kinetic energy of the particle. The total kinetic energy has two parts, translational part and rotational part. for the...
Homework Statement
A uniform cylindrical wheel of mass ##m_{1}## and radius ##R_{1}## rotates with angular velocity ##\omega_{1}##. It lies a certain distance (along the same axis) from a static wheel of radius ##R_{2}## and mass ##m_{2}##. The wheels are then pushed against each other with a...
I have a question, let’s say I’m holding a long piece of wood such as. 1’ x 6’ plank and I’m rotating it in a circle by spinning around with my hands extended, I suddenly let go, what happens to the velocity of the wood since every point on the wood that is a different distance from the center...
This is something related to my job.
There are two components A & B both traveling the same direction but at a different velocity. I can find out the exact velocity of both the components when they just hit each other, thus relative velocity is known.
Is there a way I find out the force...
Homework Statement
in the attached file
Homework Equations
Momemtum = mass - velocity
The Attempt at a Solution
I solved it E. Since object 2 has the larger mass, the effect is less and will move backwards a little bit.
Homework Statement
[/B]
A skier (mass M = 100 kg) going down a slope with inclination θ = 30°, sliding in a fluid-like snow (viscosity μ = 100 mPa*s) of thickness h = 0.01 m, using a pair of skis, each one with a surface area of As = 0.15 m2, reaches terminal velocity vt after some distance...
Homework Statement
I read the expression E=fRT/2 where E is internal energy of ideal gas and f is degrees of freedom, and ##V_{rms} = \sqrt{\frac{3RT}{M}}## Since internal energy for an ideal gas is purely kinetic (according to KTG) I can write 1/2 mv^2 = fRT/2. Now H2 is a diatomic molecule...
I apologize ahead of time for the simplicity of the question, but this has really been bothering me.Given the de Broglie relation, assuming natural units, where ##\hbar = 1##:
\begin{equation}
\begin{split}
\vec{k} &= M \vec{v}
\end{split}
\end{equation}My question regards velocity and...
Hi,
This is my first post on the PhysicsFormus
I am trying to design an inlet and outlet for an axial fan and calculate velocity and pressure profiles in the duct. See the sketch attached. The ultimate goal is to carry out a CFD study but I was wondering if there is an analytical solution for...
If talking about a particle rotating around an axis away from it by r. if the particle is moving with constant angular velocity ω. is the linear velocity constant or no?
Now what I know is that since we have Vt= ωr, so r doesn't change, as well as ω, so Vt is said to be constant. but I think...
Homework Statement
So i have this lab where I am supposed to push a car up an inclined ramp. I record the time it takes for the object to reachest the highest point on the inclined ramp before it goes back down. I am supposed to create a position vs time graph, velocity vs time graph, and...
Homework Statement
An object moves at constant speed in a circular path. True statements about the motion include which of the following?
a) the velocity is constant
b) the acceleration is constant
c) the net force on the obj is 0 since its speed is constant
Homework Equations
hm none...
Hello all,
This post is in reference to a previous homework post, found here:
https://www.physicsforums.com/threads/show-that-f-gamma-3-ma.338744/
That thread is closed to further replies. Probably because it's nearly 10 years old.
That thread is about deriving relativistic force from the...
Homework Statement
An electron and a proton are each placed at rest in an electric field of 687 N/C. What is the velocity of the electron 56.5 ns after being released? Consider the direction parallel to the field to be positive. The fundamental charge is 1.602×10−19 C, the mass of a proton is...
Homework Statement
3. (a) If an object's acceleration is zero in one inertial reference frame then is its acceleration zero in all other inertial reference frames? (b) If an object's velocity is zero in one inertial reference frame then is its velocity zero in all other inertial reference...
Homework Statement
Use the graph (attached below) to determine the time intervals when the velocity is positive, negative, or zero.
Homework EquationsThe Attempt at a Solution
The graph is of a position function.
Velocity is the derivative of position.
Velocity will be zero when the derivative...
https://www.nikhef.nl/~h73/kn1c/praktikum/phywe/LEP/Experim/3_2_03.pdf
In direction lab. I wonder why frequency of oscillator set at 50 s^(-1) ?
I want to know if the frequency affects the speed of paricles?
Homework Statement
What will be the wave velocity, if a string of 100 cm length is in a 10 kg-wt tension forms 9 nodes when vibrated and becomes symphonic to a 50 Hz tuning fork. Given, Cross sectional area of string, $$A=4.95 mm^2$$ & density, $$d = 0.25 g/cc$$?
Homework Equations
$$...
I have read that the velocity of a body through spacetime is equal to 'c'.
Can I therefore draw a spacetime velocity diagram (triangle) with sides: "v" velocity through space...
Homework Statement
A ball is thrown upward with a speed v 1. The ball reaches a maximum height of y=h. What is the ratio of the speed of the ball,v 2 , at y=h/2, to the initial upward speed of the ball,v 1 , at y=0?
Homework Equations
I attached a picture.
We are currently studying the four...
Homework Statement
Imagine we are observing two aeroplaes from the ground and let their velocities be ##\mathbf{u}## and ##\mathbf{v}## respectively. Assume that the first plane has radar equipment permitting a measurement of the speed of the other plane relative to itself. The velocity so...
Homework Statement
The equation is given:
v = f(t) = (mg/b)(1 - e^((-b/m)t))
Where v is velocity, m is mass, g is 9.81 and b is a constant of proportionality
I need to find the function k(x), where x is distance from said body's initial position.
2. The attempt at a solution
v = f(t) =...
Homework Statement
Determine the initial velocity of a projectile that reuturns to launch level 10.0 seconds after it is launched and lands 300.0m away from the launch site.
Homework Equations
Δx=v0xt
Δy=v0yt+1/2gt2
The Attempt at a Solution
[/B] 300=v0x(10)
v0x=30m/s
I don't...
Homework Statement
Raindrops fall from a broken gutter at 1.0 s intervals to the ground , 19.6 m below
Neglecting air resistance and taking g as 9.81 calculate
the time for each drop to reach the ground
velocity of the drops as they reach the ground
speed of drop at the height of 14.7 m
I...
Homework Statement
My question is, how do I show that speed is equal to group velocity? More information at https://imgur.com/a/m6FwNaG
Homework Equations
v_g = dw/dk
The Attempt at a Solution
Part a is substitution, part b uses v_g = dw/dk, part c is multiplication by h-bar, but I am stuck...
Homework Statement
How to find the velocity of the air flow around the aerofoil?
Homework Equations
U - freesteam velocity
β - angle of wing camber
The Attempt at a Solution
To find the velocity of the air flow at each section of the aerofoil, am I right to say that the horizontal velocity...
Homework Statement
A photon of wavelength ##\lambda_i = 200## pm hits an electron at rest, and is scattered exactly backwards. Find the approximate recoil velocity v of the electron using momentum conservation.
Homework Equations
Comptons Scattering:
$$\lambda_f = \lambda_i...
<Moderator's note: Split from another thread and thus no template.>
I am working on my special relativity assignment right now, and it said to find the velocity of an object when it hits the ground. The height the object is launched at is > 0.
Question: comparing that velocity to the...
Homework Statement
[/B]
So here is my question: I asked you about a solution approach/solution for the following task: Two rail paths cross at an angle of 145 °. With a constant speed of 60 km/h, they just drive along their tracks, and each of them repels steam/smoke flags, which, among other...
Homework Statement
The position of a particle moving along the x axis is given in centimeters by x = 9.35 + 1.03 t3, where t is in seconds. Calculate the instantaneous velocity when the particle is midway between its positions at t = 2.00 s and t = 3.00 s.
Homework EquationsThe Attempt at a...
Homework Statement
I'm simulating a warehouse (in Unity) where forklifts and other vehicles transport stuff from point A to point B. The routes are modeled as a graph with vertices and edges. Every transport is saved as a task in a backend system with the relevant data such as starting time...
Homework Statement
AB is a rod of length 10 m that is leaning against the wall. Given variables are shown in the diagram. Find angular velocity of A wrt B.
https://imgur.com/a/8bEdYhN
I have a doubt in one step that I will highlight in "The attempt at a solution" part.
Homework Equations...