What is Velocity acceleration: Definition and 21 Discussions

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.

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  1. Monsterboy

    Zero velocity for a time interval, what about acceleration?

    For a particle moving in a straight line, if the velocity is zero for a time interval, the acceleration is zero at any instant within the time interval. I am told the above statement is true. If I look at the equations v = dx/dt a = dv/dt It looks like if the velocity is zero for a time...
  2. Huzaifa

    B Acceleration of Moving Particles: Explained

    I am not able to understand the following paragraph from my Physics textbook;
  3. J

    A Derek Muller and UCLA Prof. Alexander Kusenko -- Downwind Physics Wager

    Derek Muller is the Veritasium YouTube channel host and he had a wager against UCLA professor Alexander Kusenko on whether a unpowered car going downwind can go faster than the wind. Derek Muller said it can go faster than the wind, while Alexander Kusenko said it only seems that way because...
  4. nick26

    Measure angular velocity and acceleration from missing tooth wheel

    Hi, I need to come up with a math model for a digital ignition system. I've been thinking about it and I think that I need to measure 2 things to be able to calculate when I have to start charging the coil. They are the angular velocity and the acceleration but how can I do it? the idea is to...
  5. Ammar2211

    A harmonic wave with a frequency and an amplitude

    For part (a), which generic function would be used? either y = f(x) = ASin(2πft + ϕ) or y(x,t)−y0=Asin(2πft±2πx/λ+ϕ) ?? Furthermore how to find out max. speed & max. acceleration of a point on the string?? Any directions please
  6. M

    Finding the change in velocity from an acceleration vs time graph

    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...
  7. PlanetGazer8350

    Calculate iron container acceleration in railgun system on the Moon

    Having a cylindrical iron container with wall thickness of 20 cm, and a total weight of 500 tons when filled with its cargo, how would you be able to calculate its required voltage and current input in a vertical railgun system (relative to the Moon's surface), with an exit acceleration of...
  8. J

    How do I find the final velocity and how high the bridge is?

    Homework Statement A rock that is thrown upward from a bridge with an initial velocity of 2.0 m/s. (Assume there is no air drag: a = -10m/s2). a) If the rock takes 4.0 s to hit the water below once the rock is released. What is the final velocity of the rock as it hits the water? b) How high...
  9. V

    Finding Maximum Velocity in Train Motion

    Homework Statement A train travels a distance of 1,2 km between two stations with an average velocity of 43.2 km/h. During it's motion, at the time t1=40s it moved accelerated, then at time t2 it moved uniformly, then at t3=40s it moved uniformly slowed. Find the maximum velocity of the train...
  10. T

    A falling stone takes 0.28 s to travel past a window 2.2 m...

    Homework Statement A falling stone takes 0.28 s to travel past a window 2.2 m tall. From what height above the top of the window did the stone fall? So from this problem I think I have these variables: vo = ? (or 0 because falling usually indicates 0 for an initial velocity?) yo = 0 y = 2.2m...
  11. Pallta

    How do I know when velocity is negative in a 1-D motion problem?

    Homework Statement Two baseballs are set in motion from the top of a 5 m tall tower. One is thrown straight down toward the ground with an initial velocity of 20 m/s. The second is thrown straight up toward the sky with an initial velocity of 20 m/s. How do their velocities compare when they...
  12. L

    How to graph Fc=mv^2/r so that the gradient = velocity

    Homework Statement Fc = mv^2/r represents the motion of a simple pendulum. Describe how this data could be graphed so that the gradient of a straight line could be used to determine the velocity of the object. Homework Equations Fc = mv^2/r The Attempt at a Solution I'm kinda stumped. I tried...
  13. M

    What are the equations for calculating velocity with varying acceleration?

    I thought i would do some digging into the wonderful world of magnets, and I found some things that... well are real head scratchers... I was wondering if anyone here could help me wrap my brain around non uniform acceleration. I'm trying to calculate velocity using distance and varying...
  14. 3

    Physics velocity acceleration and force -- Project

    Homework Statement We did two trials she didn't really go over it. first trial (1m, 1.50 seconds), (1.30m, 2.00 seconds) (1.5, 3.22); second trial (1m, 1.45), (1,30m, 2.03), (1m, 1.46) The mass of the weighted object is 50 and 200 g for the one in the car. We measured how far the toy truck...
  15. N

    2 Questions about motion in 1 direction

    So I have 2 questions to answer for my physics class and I'm not quite sure what to do. Here are the two questions and I was wondering if someone could possibly point me in the right direction. I'm not asking for the answers I just kind of want a rough idea of where to start. Thank you 1. An...
  16. P

    Resultant Velocity of Thor's Hammer

    Homework Statement m Homework EquationsThe Attempt at a Solution
  17. S

    Water Pressure Velocity Acceleration (dv/dt)

    I am having trouble solving this problem. Any assistance is greatly appreciated. Water is discharged from a pipeline at a velocity of v given by v=1192p^(1/2), where p is the pressure (in psi). If the water pressure is changing at a rate of 404 psi/second, find the acceleration (dv/dt) of the...
  18. S

    Velocity Acceleration and Displacement

    Homework Statement Hi am a physics beginner love it but seem to have issues with understanding Linear motion .. Anyway i have a question ..will be glad if could help . " A car moves along a road in such a way that the distance x ,traveled in a time t ,is given by x=a+bt(to the power 3)...
  19. T

    Angular velocity acceleration

    1. a solid sphere (I=0.4mr^2) of mass 1.5 kg and radius 15 cm moves down a 35 degrees incline 7m long. Assuming it started from rest, what is its angular velocity in rad/s at the bottom of the incline? a)71.27 b)32.25 c)49.98 d)61.69 3.i tried by plugging in the values and trying to...
  20. T

    Velocity Acceleration and Gravity

    In physics we are studying velocity acceleration and gravity. Either i am stupid or am not understanding this, but i just can't seem to understand the material. for example i don't know which formula to use for which story problem, for example(Please do not answer the problem) With a cruising...