What is Constant acceleration: Definition and 340 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,






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.

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  1. A

    Constant acceleration problem with a car

    1. Question to problem A car moving with constant acceleration covered the distance between two points 57.9 m apart in 5.02 s. Its speed as it passes the second point was 14.4 m/s. (a) What was the speed at the first point? (b) What was the acceleration? (c) At what prior distance from the first...
  2. Mr Davis 97

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  3. Erenjaeger

    Calculating Time for Constant Acceleration: Motorcycle Velocity Change

    Homework Statement A motorcycle has a constant acceleration of 2.80 m/s2. Both the velocity and acceleration of the motorcycle point in the same direction. How much time is required for the motorcycle to change its speed from (a)40.9 to 50.9 m/s, and (b)70.9 to 80.9 m/s? [/B]Homework Equations...
  4. M

    How to interpret the equation of position with constant acceleration?

    x = x0 + v0 * t + 1/2 * constant acceleration * t^2 So this is supposed to be very very simple physics, but I still feel like there's a part of this equation I don't fully understand. The first term is the initial position of the body at t=0. The second term is the initial velocity at t=0...
  5. Bill48

    Constant Acceleration Ratio to Constant Velocity

    Homework Statement A car traveling at an unspecified constant speed passes a parked motorcycle cop. The motorcycle accelerated at an unspecified constant acceleration and reaches the car at unspecified distance d. At what point did the motorcycle's speed match that of the car, expressed as a...
  6. Dr Wu

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  7. C

    Solve UROV Fluid Mechanics Homework: Max Vel, Time, Distance, Drag Force

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  8. somethingswrong

    Questioning Constant Acceleration & Sanity - Is Something Wrong?

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  9. REVIANNA

    Classical mechanics : constant acceleration

    Homework Statement Two cyclists, Anant and Beth, are standing on a straight road a distance d=22.0 m apart. Simultaneously, they begin to move toward each other, Anant with acceleration a_A=0.2 m/s^2 and Beth with acceleration a_b=0.10 m/s^2. Just as they begin to move, a bee, sitting on...
  10. L

    Which one of these motions is at constant acceleration?

    Homework Statement Which one of these motions is at constant acceleration? A) A car moving at a constant speed and constant direction. B) A train making stops along its route. C) A moon orbiting a planet. Homework EquationsThe Attempt at a Solution I believe that A is an acceptable answer...
  11. D

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  12. L

    Motion w/ Constant Acceleration

    Homework Statement "A jet plane is cruising at 300 m/s when suddenly the pilot turns the engines up to full throttle. After traveling 4.0 km, the jet is moving with a speed of 400 m/s." Homework Equations "What is the jet's acceleration, assuming it to be a constant acceleration?" The Attempt...
  13. K

    How long will it take for the baseball to reach John again if he misses it?

    Homework Statement [/B] 1. Rob throws a baseball upwards at 14.2 m/s. His friend, John, is sitting in a tree 4.5m above Rob. a. Calculate how long it will take to reach John. b. If John misses the ball as it moves upwards, how long will it take to reach John again. Homework Equations...
  14. M

    Calculating Time and Acceleration in Constantly Accelerating Cars

    In a car moving at constant acceleration, you travel 250 m between the instants at which the speedometer reads 40 km/h and 80 km/h. How many seconds does it take you to travel the 250 m? What is your acceleration? I have thought of finding the average of 40 km/h and 80 km/h to start the problem...
  15. SpaceW

    Motion with constant acceleration

    Homework Statement A person is standing over a well and drops a rock. After 2.4 seconds he hears a rock splashing into the water. Take the speed of sound to be 300m/s and calculate the depth of the well. Homework Equations x=v/t for constant velocity x=1/2at^2 for accelerated motion The...
  16. O

    Vt=d doesn't seem to hold true w/ constant acceleration

    Hello,Lets say I start off with constant acceleration of 1 m/s^2, and I want to evaluate it at 3 seconds. a = 1. a(3) = 1 then, since at=v, v(t) = at = 1(3) = 3m/s then I can work backward v/t = a = 3/3 = 1 then, since vt = d d(t) = vt = 3(3) = 9 then I can work backward d/t= v =...
  17. P

    One-Dimensional Motion with Constant Acceleration

    Homework Statement A rock is released from rest from the top of a very high cliff, and accelerates downward at g. Approximately how far does the rock travel in the first 7 seconds of its free-fall? (Assume no air friction.) Homework Equations X=Xo+VoT+1/2AT^2 The Attempt at a Solution I...
  18. J

    How can constant power produce constant acceleration?

    The way I see it, a constant supply of power, say from the engine in a car to its wheels, will cause it to accelerate at a decreasing rate because the kinetic energy the power supplies is proportional to the velocity squared. That makes sense because going faster will cause the car to encounter...
  19. S

    What is the final velocity of a car with constant acceleration?

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  20. P

    Finding constant acceleration, unit difficulty

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  21. bananabandana

    Does Acceleration Affect the Stability of an Atwood Machine in an Elevator?

    Homework Statement Please see attached for diagram. We know that the elevator arm is horizontal when the lift is stationary, with ## M_{1}=\frac{4M_{2}M_{3}}{(M_{2}+M_{3})}## It wants us to find out if this is still the case when the lift is accelerated upwards at a constant velocity ##g##...
  22. E

    Metric for uniform constant acceleration?

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  23. Q

    Constant acceleration of gravity

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  24. L

    Apply impulse to a wheel creates constant acceleration?

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  25. goonking

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  26. J

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    < Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > Hello, I'v been trying to find an answer for this question for quite some time, I always hit a complex trigonometric equation or a 4th degree polynomial equation. any help would be very much...
  27. E

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  28. P

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  29. Elvis 123456789

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  30. Entangled Cat

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  31. A

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  32. M

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  33. F

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  34. T

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  35. P

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  36. F

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  37. Greg Bernhardt

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  38. Adjoint

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  39. Adjoint

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  40. P

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  41. Caolan

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  42. H

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    Greetings, I'm having some issues with a problem that I is related, though not identical, to Bell's spaceship paradox (this is not for a homework or anything, it just sort of occurred to me when I was thinking about something else). Consider two particles that are initially at rest in some...
  43. T

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  44. C

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  45. M

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  46. M

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  47. B

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  48. D

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  49. B

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  50. R

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