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 All,
I am struggling with the question (attached) and was hoping to get some guidance and explanation on how to solve it.
I`m thinking that it is force down is equal to force up? But I could be wrong.
Any help greatly appreciated.
Regards,
James
Homework Statement
A rope of length L and mass m is attached to the ceiling and folded at mid length. The free end of the rope is held against the ceiling, then dropped at time t=0.
a) Calculate the velocity of the free end as a function of y, its distance from the ceiling.
b) Calculate R...
Homework Statement
A mirror is moving to the right with a velocity 15 m/s, and an object is moving to the right with a speed of 5m/s. All speeds are wrt ground. Find the velocity of image wrt ground.
Homework EquationsThe Attempt at a Solution
I present to you two probable solutions:
1) Using...
Hello
What is the meaning of the average velocity of gas molecules calculated by Boltzmann distribution (in kinetic theory of gases)?
Does all molecules have the same average velocity?
You may think you've seen this before, since I've seen similar discussions in the archives of this, but I think I've distilled the thoughts down to a couple of facts that contradict the common beliefs regarding relativity.
Let me preface this with a basic observation: Lorenz invariance does not...
Suppose a spaceship is flying past me, an observer on earth, at .86c. A traveler on the ship has a ball which is attached to a string which is 100 feet long in the ship frame. The traveler grabs the string and throws the ball out of the front window of the ship at a speed of 100 feet per second...
Homework Statement
A particle moves along a parabola on the x-y plane with equation ##y^{2}=2px## with constant speed ##1000m/s##.What is the magnitude of its acceleration?
Homework Equations
Parametric equations ##\vec{r}=(b^{2}t^{2}/(2p),bt)##.
The Attempt at a Solution...
Homework Statement
Two balls of mass m are attached to ends of two, weigthless metal rods (lengths l1 and l2). They are connected by another metal bar.
Determine period of small oscillations of the system
Homework Equations
Ek=mv2/2
v=dx/dt
Conversation of energy
2πsqrt(M/k)
The Attempt at a...
I'm setting up a lab for my class and I've found this equation, but I can't find where a constant value is coming from.
"...the speed of rotation of the rings is related to their radius (from the center of Saturn) by the following equation:
where R is the distance from the center of Saturn...
I'm trying to understand the following derivation. Starting with the one-dimensional equation for a traveling wave ##u = u_0 \exp{[j(\omega t - \beta z)]}## the goal is to derive the phase relation between strain and velocity. The author first derives the relationship between strain and particle...
Homework Statement
A metal strip 6.5cm long, 0.88cm wide, and 0.76cm thick moves with constant velocity, magnitude v along positive y-axis, through a magnetic field, B=1.2mT along positive z-axis. A potential difference of 3.9x10^-6V is measured between points x1 and x2 (as shown in...
Homework Statement
I have been set this question and I am struggling with parts b and c. I think I am nearly there but can't quite get over the line. Please could someone give me a nudge in the right direction.
[/B]
1. (a) For the mechanism shown in FIGURE 1 determine for the angle
θ = 45°:
(i)...
I'm a PhD student who's taken GR, so I have studied gravity and cosmology, and we have the underlying assumption of homogeneity and isotropy, but since this assumption comes from how we've calculated the distribution of galaxies in the visible universe I want to make sure I really understand it...
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Homework Statement
This question is actually two question. We have two hollow frames - one is rectangular and another is triangular. the rectangle is rotated and fixated such that the angles in shape are ##\alpha , \beta = 90 - \alpha## and the angle of triangle is ##\alpha##. We have two balls...
1. The problem statement.
A tennis ball of mass m moving horizontally with speed u strikes a vertical tennis racket. The ball bounces back with horizontal speed v.
Homework Equations
p = mv
The Attempt at a Solution
My answer was m(v-u), meaning the final momentum (mv) subtracted from the...
Homework Statement
There is a train of length d and speed v. It is heading towards a hill with height h and length of each side l. What velocity requirement must be met so that the train can go up and down the hill?
Homework Equations
Ek=m⋅v2/2
Ep=m⋅g⋅h
The Attempt at a Solution
I'm basically...
Hi!
I was trying to understand circular motion and came across two problems. I would really appreciate if you could help me with those.
Question 1:
In the picture below let's assume that the angle θ is 1 radian, i.e. 57.3°, radius is 1 m. It would mean that the length of arc AB is also 1 m...
Can someone please check my work to this?
The reflecting telescope is deployed in low Earth orbit( 600km) with each orbit lasting about 95 min. use the linear velocity formula to solve the problem.
I did 300 * 95 min = 28500. Can someone check my work please? if someone could check it today...
I have a question which asks me if an object with a mass of 2250kg starts from rest at the top of a frictionless ramp 10m long and is at an angle of 10 degrees horizontally, what is the velocity of the object the moment it reaches the bottom of the ramp?
I have been trying to work out this...
Homework Statement
Please look at the attached screenshot.
This problem is really confusing for me and I can't seem to make much sense out of it.
Homework Equations
Ei = Ef
The Attempt at a Solution
As you can see, I did get (a). (The other checkmarks, I guessed — there were only two...
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
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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...