Questions tagged [velocity]

The time rate of change of the position of an object

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Buoyancy - Droplet of Oil in Water

If I place a droplet of oil, which is less dense than water, at the bottom of a glass of water, it should start to rise in the water due to the buoyant force. Will the oil droplet start rising faster ...
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What is the orbital velocity of Pluto around the Pluto-Charon barycenter?

Charon is so massive relative to Pluto that they both orbit a point that is outside Pluto. The distance from the center of Pluto to the barycenter is given by: $$r = \frac{a}{1+\frac{m_{pluto}}{m_{...
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Will a tennis ball tossed straight up in a airplane cabin move towards the tosser or will its distance from the tosser remain the same? [duplicate]

If I am in a pressurized airplane cabin and I toss a tennis ball into the air, will the ball move towards me? My thinking is that though the ball is in an air bubble that is moving as a whole at the ...
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Calculate ball speed and direction from forward angular speed and sideways force [closed]

I have a mounted arm with a ball attached to the end. It has a potentiometer that de-facto measures the angle between the arm and and the mount. below the ball is a newtonmeter (actually a weight ...
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Theoretical question about velocity and acceleration

Imagine you have a ventilator that is spinning madly an creating strong air up force upwards. Then you put in the middle with a holder a paper ball. Then some-have detach the paper from holder. Sure ...
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Very tricky velocity, distance calculations [closed]

I have a constantly moving (no mass, no dumping & no gravity for sake of simplicity) object with speed 4m/s at point p1. Object is flying into direction p2 what is 8m away. What I want is that ...
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How would you respond to the misconceptions “Velocity is constant when acceleration is also constant.”..cont'd [closed]

...."Velocity is always linear", and "acceleration is always quadratic". What fundamental concept is being misunderstood here?
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Vector of normal acceleration [closed]

How can I calculate the value of a normal vector of acceleration in a point, having the velocity vector and the acceleration vector in that point? For Example: I have the velocity vector (2,5) and the ...
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Calculate circular velocity by comparison [closed]

So I have this problem where I have to calculate circular speed but I don't have the mass. I can only do this by comparison. So a ball rotates at $2.4 \ ms^{-1}$ with a radius of $0.8$ m. How much ...
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Thought process at higher velocities

Time passes slower for objects that move at near speed of light . Since brain activity is based on signals that also need time to travel a certain distance, does the effect cancel itself out, or would ...
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A Problem with velocity vector

I am having a conceptual problem. I understand why the definition of the velocity of a body moving in one dimension is the derivate of its position coordinate. But I don't get why the velocity vector ...
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Why is pressure over the wing lesser than the pressure on the bottom? [duplicate]

Why is the flow above the wing faster than the lower one? Most people say it's because the pressure above is lesser than the bottom one But for the pressure to be low... The velocity must be high.So ...
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Vapour clouds and the speed of sound

I've been thinking about this question for a while and I didn't get to any conclusion yet. When an aircraft flies faster than the speed of sound (specifically when it achieves it) a cloud of condensed ...
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Why does the term $-\frac{q}{c}\frac{d\vec{A}}{dt}$ play no part in the Lagrangian of a charged particle in an electromagnetic field? [duplicate]

A common derivation of the Lagrangian of a charged particle in an electromagnetic field starts with the Lorentz force that is rewritten in terms of the electromagnetic potentials $\Phi(\vec{x})$ and $\...
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Is instantaneous speed always equal to the magnitude of instantaneous velocity?

Is instantaneous speed always equal to the magnitude of instantaneous velocity? What about the infinitesimal time duration when the direction changes? How can it ALWAYS be equal?
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Convective Air Velocity

Consider there is a hot plate which causes natural convection in a closed environment of air over the hot plate. Is there any exact formula to find velocity of air flow? If there is please cite the ...
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How is acceleration calculated when only the direction of velocity changes and the magnitude remains the same? [duplicate]

How is acceleration calculated when only the direction changes and the magnitude remains the same? Guys, I know that my previous examples didn’t make sense and I’m sorry because I’m totally new to ...
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What is the direction of the velocity $v=\sqrt{2gy}$ vector? Is it tangential? If so, why?

I was trying to obtain the brachistochrone as a function of time, and I failed several times because I wrongly assumed that the $v=\sqrt{2gy}$ vector points downwards (vertical vector). However, in ...
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Why friction losses depend on velocity squared?

This is the reason that suction pipes of centrifugal pumps are most of the times much wider than the discharge pipes and that restriction of blood flow in arteries is always an alarming event. Does ...
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Rotational velocity due to Dark matter

I was wondering if we can predict the rotational velocity due to dark matter in this way: Consider that we theoretically derived the rotational velocity of a galaxy ($v_{the}$). Then from experiment ...
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Why don't we use vector sign for quantities in 1D motion? [duplicate]

My school textbook says that we don't need to use unit vectors (i ,j,k) to represent the direction of vectors in 1D motion as + and - sign indicate direction. But that is creating a lot of confusion ...
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Value of Final Velocity of Dropped Object

When an object such as a feather is dropped from a height, the initial velocity is said to be $0$. I would assume that the final velocity would also be $0$ as when the feather reaches the ground, it ...
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Are acceleration and velocity simultaneous? [closed]

I would think yes because, if a rope tied to a swinging rock breaks, the rock flies off in the direction that is perpendicular to the direction of the last instant of the acceleration. The ...
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Mathematics for Space-Piracy [closed]

I have been developing a science fiction novel, and something akin to the following mathematics problem has arisen: (Assume Newtonian mechanics for the moment.) Alice is a medium-distance space-...
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Kinematics and vectors and velocity [duplicate]

I directly applied the parallelogram law addition but I didn't got the correct answer my question is that does the parallelogram law of addition doesn't apply while adding velocities why didn't it ...
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What is the orbital velocity of the primary in a two-body system where the barycenter lies outside the primary?

For the Sun-Earth system, the barycenter lies more or less at the center of the Sun and so the orbital velocity of the Earth can be calculated using the formula $V = \sqrt{\frac{GM}{R}}$. However for ...
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Why is jerk/jolt unintuitive as opposed to acceleration and velocity?

Going from position to velocity to acceleration makes sense. But suddenly acceleration to jerk is hard to grasp. Why is that?
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Proper Velocity $v$ Relative Velocity

I understand the proper velocity is the velocity as measured by the traveler, and relative velocity as measured by the observer. Relative velocity is limited to $c$, but is that also true of proper ...
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Components of velocity under impulsive motion [closed]

I am getting confused when it comes to motion of two movable bodies joined by the ends of a string wherein one of them is given some velocity (making a certain angle to the string joining the bodies). ...
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Is the wave phase of a sound wave always positive?

I guess this is a pretty basic question, but I am not certain about its answer (since I am still studying in high school). Let's say we are given the equation of the following sound wave and we are ...
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Average Velocity ($\vec{\bar{v}}$) Intuition and Analogy for Non-Uniform Acceleration

Background So I was trying to make as much sense out of kinematics through intuition after having taken my first semester of university physics, and I've stumbled onto a dillema that I can't seem to ...
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How does high velocity cause low pressure? [duplicate]

Bernoulli's principle states that air molecules moving with high velocity create an area of low pressure which in turn causes an object to fly, but how does high velocity cause low pressure?
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Intuition about the harmonic mean when running multiple laps with different velocities

If I run two laps (= same distance) at different velocities $v_1$ and $v_2$, it is easy to derive algebraically that the mean velocity is given by the harmonic mean of $v_1$ and $v_2$ $$ \bar v_{\text{...
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Does “$\rm m/s$” mean the same thing when used for instantaneous velocity and for mean velocity?

The following question on Philosophy SE https://philosophy.stackexchange.com/q/73366/ relies on this "given" "suppose that the instantaneous velocity of object A is $1$m/s and that the mean ...
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Speaker on bicycle - would it propel the rider forward?

You strap a super powerful speaker on your back, blast it on max volume. Would it propel you forward?
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External force dependent on velocity on a Lagrangian [duplicate]

The question I have is, what conditions must satisfy an external force dependent on velocity so it can be a part of the lagrangian and Euler-Lagrange equations are still true.
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Does tangential acceleration change with radius? [closed]

Do tangential velocity and tangential acceleration change with radius (change of radius on the same object)? For example consider a spinning disk. Does the equation $$a_t = \alpha R$$ (where $a_t$ ...
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Is the initial horizontal velocity of a kicked ball also it's maximum horizontal velocity? [closed]

The horizontal velocity that the ball acquires from the impact of your foot, will this be the maximum velocity, or will there be some horizontal acceleration at first, after which drag will slow down ...
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Acceleration as a function of position and time

I know if you have an acceleration as a function of $t$, $a(t)$, to find the velocity you simply integrate $a(t)$ with respect to $t$. Moreover, if the acceleration was a function of position, $a(x)$, ...
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Electron's velocity speed and angle with time [closed]

An electron follows a helical path in a uniform magnetic field, does its velocity, speed and angle changing with time?
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Why does speed affect turn radius when turning a motorcycle given a fixed lean angle?

I have been looking at a formula which is supposed to calculate the lean angle and turn radius which is $$\theta=\arctan\left(\frac{v^2}{gr}\right)$$ I do not understand how velocity effects turning ...
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Non-inertial uniform velocity frame

Suppose, an observer is on a train which has only platform to stand but no walls. The train is moving with a constant velocity with reference to railroad. While moving, the observer feels strong wind ...
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In the equation: $a = dv/dt$ , is $dt$ the time taken to achieve that instantaneous acceleration?

If you solve for $dt$ from $a = \frac{dv}{dt}$ , is it the time taken to to achieved that instantaneous acceleration? $a$ : acceleration $v$ : velocity $t$ : time
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Dynamic Bend Angle During Explosion Bonding Process (Simple Vector Problem)

For some reason this makes no sense to me. The setup is pictured: A flyer plate at a fixed distance from a base plate has explosive placed on top and is accelerated into the base. $V_D$ and $V_C$ are ...
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What does the first derivative of (2-norm) distance with respect to time tell us?

My basic physics' knowledge is a little rusty. My apologies in advance. I know that the first derivative of position or displacement with respect to time is the instantaneous velocity. Suppose I have ...
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The relation between rebound angle and angular frequency of dropped spinning ball?

The dropped ball is spinning around a horizontal axis and bounces away from the vertical at an angle. I tried solving this problem using the angular and linear momentums with the following logic: ...
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Why don't these conversions of time between reference frames seem consistent? [closed]

I am a student and due to school closures I am reading ahead in physics. I have been learning about relativity and I made up a problem for myself. You can see a diagram that I drew below: The diagram ...
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Velocity of particle due to acceleration. Special relativity

I understand how to do transformations of four velocities, acceleration and so on under Lorentz boosts. However after all I have learned in special relativity I still don't know how just an ordinary ...
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When the rate of acceleration changes it's sign how does the velocity change?

When the rate of acceleration changes its sign how does the velocity change? When another derivative of distance with respect to time is increased how does it affect factors like displacement and ...
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Constant or Uniform Velocity and acceleration

I get confused understanding Constant or uniform Velocity and acceleration when I understand constant speed which means that same distance traveled at same time. So constant or uniform velocity ...

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