What is Instantaneous acceleration: Definition and 31 Discussions

In mechanics, acceleration is the rate of change of the velocity of an object with respect to time.
Accelerations are vector quantities (in that they have magnitude and direction). The orientation of an object's acceleration is given by the orientation of the net force acting on that object. The magnitude of an object's acceleration, as described by Newton's Second Law, is the combined effect of two causes:

the net balance of all external forces acting onto that object — magnitude is directly proportional to this net resulting force;
that object's mass, depending on the materials out of which it is made — magnitude is inversely proportional to the object's mass.The SI unit for acceleration is metre per second squared (m⋅s−2,




{\displaystyle {\tfrac {\operatorname {m} }{\operatorname {s} ^{2}}}}
For example, when a vehicle starts from a standstill (zero velocity, in an inertial frame of reference) and travels in a straight line at increasing speeds, it is accelerating in the direction of travel. If the vehicle turns, an acceleration occurs toward the new direction and changes its motion vector. The acceleration of the vehicle in its current direction of motion is called a linear (or tangential during circular motions) acceleration, the reaction to which the passengers on board experience as a force pushing them back into their seats. When changing direction, the effecting acceleration is called radial (or orthogonal during circular motions) acceleration, the reaction to which the passengers experience as a centrifugal force. If the speed of the vehicle decreases, this is an acceleration in the opposite direction and mathematically a negative, sometimes called deceleration, and passengers experience the reaction to deceleration as an inertial force pushing them forward. Such negative accelerations are often achieved by retrorocket burning in spacecraft. Both acceleration and deceleration are treated the same, they are both changes in velocity. Each of these accelerations (tangential, radial, deceleration) is felt by passengers until their relative (differential) velocity are neutralized in reference to the vehicle.

View More On Wikipedia.org
  1. WMDhamnekar

    I How Does Angular Velocity Affect Instantaneous Acceleration in Rotating Systems?

    Homework Statement:: Find the instantaneous acceleration of a projectile fired along a line of longitude (with angular velocity of ##\gamma##constant relative to the sphere) if the sphere is rotating with angular velocity ##\omega##. Relevant Equations:: None Find the instantaneous...
  2. J

    Instantaneous acceleration from Velocity-time graph

    Homework Statement https://imgur.com/a/bvcxjNy Homework Equations Since the elevator is accelerating upwards, N - mg = ma or N = m(g+a) ------------ (1) The Attempt at a Solution In order to get the accelerations at that instant, I drew a tangent at that point and used v2 - v1/t2 - t1 = a...
  3. james digel

    Question: How do I determine instantaneous acceleration using given data points?

    Homework Statement A. Calculating instantaneous acceleration using formula: 1. According to ‘Table II’ data below: i. t=5 ii. t=15 iii. t=25 iv. t=35 v. t=45 Homework Equations The Attempt at a...
  4. navneet9431

    Condition for Instantaneous Acceleration = Average Acceleration

    Homework Statement [/B] Look at this graph.Is Instantaneous Acceleration=Average Acceleration here? Please explain your solution. What should be done to check whether Average Acceleration=Instantaneous Acceleration? Homework Equations Average Acceleration motion equations The Attempt at a...
  5. P

    Resultant force of spring at the instant of release?

    Homework Statement What would the resultant force have been at the instant of release, if a 350 g mass were suspended from your spring, pulled down 3 cm and released? What would have been the instantaneous acceleration at the moment of release? The questions pertain to an experiment with a...
  6. parshyaa

    What is instantaneous acceleration?

    How their can be instantaneous acceleration, its impossible to have change in velocity at a particular position(instant), we can have velcoity or speed at a particular point but how can we have change in velocity at a particular instant?
  7. Q

    How do pressure gradients develop instantaneously in Bernoulli flow?

    Hi I am having trouble understanding how Bernoulli’s pressure gradients develop I know the equation in a steady flow state (after the developed state ‘flushes’ thru) but I want to understand what mechanism lowers the pressure and increases the speed as the flow develops The continuity...
  8. R

    What is the Significance of Instantaneous Acceleration in Classical Physics?

    i understand why acceleration has much significance in Classical physics. But something that has intrigued me is why my lessons focus a great deal on instantaneous acceleration. I have had quite a hard time in figuring out what the practical application of this concept is! Help me out guys!
  9. jalessandrom

    Instantaneous acceleration from coordinates?

    Homework Statement The coordinate of an automobile in meters is x(t) = 5 + 3t + 2t2 and y(t) = 7 + 2t + t3, where t is in seconds. What is the instant acceleration of the car at time t = 2 s? ANSWERS: A. 10.2 m/s2 B. 9.5 m/s2 C. 7.9 m/s2 D. 15.0 m/s2 E. 12.6 m/s2 Homework Equations ains =...
  10. P

    Instantaneous Acceleration from a Velocity-Time graph

    Homework Statement A test driver is testing a new model car with a speedometer calibrated to read m/s rather than mi/h. The following series of speedometer readings were obtained during a test run along a long, straight road: Time (s): 0 2 4 6 8 10 12 14 16 Speed (m/s): 0 0 2 6 10 16 19 22...
  11. karush

    MHB Est instantaneous acceleration of the car at t=20

    A car is traveling along a straight road with values of its continuous velocity f(t) in ft/sec as given t \ \ v(t) 0 \ \ 90 10 \ \ 75 20 \ \ 80 30 \ \ 100 40\ \ 90 50 \ \ 85 60 \ \ 80 Est the instantaneous acceleration of the car at t=20 sec. there is no eq for...
  12. T

    Instantaneous acceleration of blocks

    Homework Statement The blocks are of mass 2 kg shown is in equilibrium. At t = 0 right spring in fig (i) and right string in fig (ii) breaks. Find the ratio of instantaneous acceleration of blocks?Homework Equations The Attempt at a Solution In fig (i) before the string is cut,(2kx)sin37° =...
  13. M

    Calculating instantaneous acceleration

    Homework Statement The position of a particle moving along the x-axis is given in centimeters by x = 9.75 + 1.50t3, where t is in seconds Calculate the instantaneous acceleration at 2.00 s. Homework Equations x = 9.75 + 1.50t3 I don't understand how i would solve for the acceleration using...
  14. L

    Instantaneous acceleration/ velocity

    Hi everyone, first time poster. I was just hoping somebody could explain instantaneous acceleration to me a bit better than my prof did. I know that we take dv / dt. But I am just having trouble applying it. Does this mean that I am putting the derivative x's position equation on top? and...
  15. A

    How to find Instantaneous acceleration with points from a graph

    Homework Statement How to find instantaneous acceleration when the velocity final is 4 m/s, the velocity initial is 1 m/s, the time final is 5 seconds, and the time initial is 2 seconds? Homework Equations The Attempt at a Solution I have no idea how to do the second derivative...
  16. E

    Instantaneous Acceleration for Uniform Circular Motion

    Homework Statement A normally functioning clock has a radius of 30cm. What is the average acceleration in the first 15 seconds if the second hand starts at 12? What is the instantaneous acceleration when the second hand is at 12? Homework Equations v = d/t a = Δv / Δt limit as Δt...
  17. T

    How to calculate instantaneous acceleration?

    This is the graph and question: http://img193.imageshack.us/img193/3489/physicquestion.jpg I cannot seem to find the instantaneous acceleration. I must be doing it wrong because I'm pretty sure to find the the inst. acceleration all i need to know is the tangent line equation. I've tried...
  18. W

    Finding Instantaneous Acceleration in a Velocity-Time Graph

    http://i52.tinypic.com/95zrsw.png ^ okay, if my velocity-time graph looks like that (it was a quick sketch), and I need to find the INSTANTANEOUS velocity at point A and point B, how do I do it? I mean, I understand the slope of the tangent = instantaneous acceleration, but this is not a...
  19. P

    Super easy driving question - instantaneous acceleration

    super easy driving question -- instantaneous acceleration Homework Statement a Person in a car is driving down a straight road. The instantaneous acceleration is decreasing with time but is directed in the same direction as the cars motion the speed of the car is constant or increasing with...
  20. S

    Instantaneous Acceleration?

    Homework Statement Find the instantaneous acceleration at 10s (see graph in attachment) Homework Equations a = dv/dt dt----0 The Attempt at a Solution I am taking an algebra based physics class and have never taken calculus before -_- I tried 0.0 and 1.0 so far Help on this problem would...
  21. C

    Instantaneous acceleration, very simple question

    Hello, I'm trying to teach myself basic physics from a book I bought at Davis-Kidd, and I've come across a problem which puzzles me to no end. It's quite simple: It's a problem that uses a graph of a baseball player's change in velocity with time. It labels 3 points of the graph and asks...
  22. S

    Average acceleration and instantaneous acceleration

    Homework Statement The acceleration of a particle moving only on a horizontal xy plane is given by a= (3t)i + (4t)j, where 'a' is in m/s*2 and t is in seconds. At t=0, the position vector r= (20m)i + (40m)j locates the particle, which then has the velocity vector v=(5m/s)i + (2m/s)j. At...
  23. M

    Finding Instantaneous acceleration from a velocity-time graph

    Graph: http://s324.photobucket.com/albums/k327/ProtoGirlEXE/?action=view&current=Capture.jpg What is the instantaneous acceleration at t2 = 31 s? I know that the instantaneous acceleration is the slope of the tangent of that point and yes I do know I have to convert it to (m/s^2). But I am...
  24. T

    Instantaneous Acceleration of a Child on a Ferris Wheel

    A child on a Ferris wheel is moving vertically upward at 6.20 m/s at one instant, and 0.150 s later is moving at 6.20 m/s at an angle of 41.5° above the horizontal. Estimate the child's instantaneous acceleration. What is the magnitude? What is the direction? (degrees below the horizon) I...
  25. L

    Instantaneous Acceleration on a Velocity-Time Graph

    [SOLVED] Instantaneous Acceleration on a Velocity-Time Graph I need to find the acceleration at a specific time (for example, 6s). I know how to do the acceleration between time intervals, slope=rise/run, a=vf-vi/t2-t1, but what do I do when I need the acceleration at a specific time? I've...
  26. B

    Finding the instantaneous acceleration

    How do you go about finding the instantaneous acceleration when given the instantaneous force and mass of an object? Example: A baseball of mass 0.13 kg is struck by a bat with an instantaneous force of 5557.0 N. What is the instantaneous acceleration of the ball?
  27. H

    Calculate the instantaneous acceleration

    Homework Statement A car's velocity as a function of time is given by Vx (t) = alpha + beta (t)^2, where alpha = 3.00m/s and beta = .100m/s^3. Calculate the instantaneous acceleration for t= 5seconds Homework Equations ax = dv/dt The Attempt at a Solution My first attempt is to...
  28. K

    Understanding Instantaneous Acceleration and Velocity in Physics

    Homework Statement can some explain it to me, how to solve? also can how to find instantaneous velocity? Homework Equations The Attempt at a Solution
  29. A

    Instantaneous Acceleration Help PLEASE ~

    Instantaneous Acceleration Help PLEASE!~~~ I have a homework problem on Instantaneous acceleration: The engine of a model rocket accelerates the rocket vertically upward for 2seconds as follows: At t=0, speed=0; At t=1s, s=5m/s; At t=2s, s=16m/s. a) find the average acceleration during...
  30. B

    Is there Instantaneous Acceleration?

    Is there such a thing as instantaneous acceleration or is it always zero? Problem gives: x(t)=8.5t^2-2t+6 and asks for instantaneous acceleration at t=3 Any help would be greatly appreciated