# What is Average acceleration: Definition and 142 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. ### Calculating Average Acceleration of a Particle Moving in a Circle

I was given two HW questions, I was supposed to solve on using ##<\vec{a}> = \frac{\vec{V}_f - \vec{V}_i}{\delta t}## and another using ##<f(x)> = \frac{\int_{x_1}^{x_2}f(x)dx}{x_2 - x_1}##, I was able to solve using the first formula but I wasn't able to do it with second (at least I got the...
2. ### Question about the average acceleration

Hello everyone, I have to find the average acceleration in the intervals 0m - 30m, 30m - 60m, and 60m - 90m. Here is the table: Position (m) 0 10 20 30 40 50 60 70 80 90 100 Time (s) 0 1,89 2,88 3,78 4,64 5,47 6,29 7,10 7,92 8,75 9,58 My teacher has given us the answers, but we have to...
3. ### Average acceleration of an arrow by a bow

Distance= (Intial Velocity + Final Velocity / 2) Time 0.75 = (0+75 / 2) Time 0.75 = (37.5) Time 0.02 seconds = Time Acceleration = (Final Velocity + Intial Velocity) / Time Acceleration = (75 - 0) / 0.02 Acceleration = 3750 m/s2 Idk if this is correct can someone help pls.
4. ### Average acceleration of a car changing speed and direction

Nevermind I found what I had to do, thank you though.
5. ### Calculating average acceleration during a time interval

Here's my calculations for (a) and (b)
6. ### Finding the Average Acceleration

Hello, so I am working on a projectile motion lab but I'm not sure what to do right now. Essentially, the lab consisted of my classmates and I using an air table to show that the vertical and horizontal components of projectile motion are independent. During one of our trials, we placed a puck...
7. ### How to find an average acceleration using an average velocity?

I calculated the average velocity in a previous problem and got 1.146788991m/s over a time of 8.72s. I know I can’t use a_ave=(Vf-Vi)/(Tf-Ti) because I don’t know the final velocity and have no way to find it. Do I multiply average velocity by time?
8. ### MHB 2.3.17 Find the average acceleration for this interval.

2.3.17 At $t=5\, s$ an object is traveling at $5 \, m/s$. At $t=8\, s$ its velocity is $-1\, m/s$ (a) Find the average acceleration for this interval. $$a_{av}=\frac{v_2-v_1}{t_2-t_1}=\frac{\Delta v}{\Delta t}$$ So $$a_{av}=\frac{-1-5}{8-5}=\frac{-6}{3}=-2 \, m/s$$ book answer \$-2\...
9. ### Do I need to consider mass in the equations?

Homework Statement a. At launch a rocket ship has a mass M. When it is launched from rest, it takes a time interval t1 to reach speed v1; at t = t2, its speed is v2. What is the average acceleration of the rocket (i) from the start to t1 and (ii) between t1 and t2? For now, I am taking...
10. ### Calculate average speed/acceleration for the given function

Homework Statement Serway Physics Chapter 2 20. An object moves along the x-axis according to the equation ##x=3.00t^2 - 2.00t+3.00##, where x is in meters and t is in seconds. Determine (a) the average speed between t=2.00s and t=3.00s, (b) the instantaneous speed at t = 2.00s and at t=3.00s...
11. ### A ball bounces off a brick wall, Find the average acceleration

Homework Statement Serway Physics Section 2.4 Acceleration 14. A 50.0-g Super Ball traveling at 25.0 m/s bounces off a brick wall and rebounds at 22.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.50 ms, what is the magnitude of the average...
12. ### 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...
13. ### Basic average acceleration confusion

Hi there, I'm struggling to distinguish why the following two equations are giving distinct answers, when the question explicitly states either could be used: v=u+at v^2=u^2+ad when v=12 m/s u=0 m/s a (average acceleration)= the unknown variable d=24 m t=4s Theoretically, the two should...
14. ### How do you work out average acceleration without time?

How do you workout average acceleration without time? I have Initial velocity ,final velocity & distance. With this I have to workout... 1) Average acceleration 2) Time take to accelerate from initial to final velocity Regards Someone a little confused
15. L

### Average acceleration vector

Question: A car is moving north at 100km/h. An hour later it is moving east at 100km/h. Its average acceleration during this hour is: a) A vector pointing northeast b) A vector pointing southeast c) A vector pointing southwest d) A vector pointing east e) Zero Attempt: I confidently chose a) A...
16. J

### Vectors, how to find average acceleration

Homework Statement At one instant a bicyclist is 20.5 m due south of a park's flagpole, going due east with a speed of 14.1 m/s. Then, 3.95 s later, the cyclist is 36.3 m due west of the flagpole, going due north with a speed of 18.3 m/s. For the cyclist in this 3.95 second interval, find each...
17. ### Average Acceleration and Time Taken to accelerate

Hi, I've been asked to solve below as part of an assignment. Below is pretty much what I've submitted but it has been concluded to be incorrect. I am unsure as to why hence the question. Is it due to the fact that I have not taken the mass or forces into consideration? I have only taken these...
18. ### Speed at Takeoff and Average Acceleration

Homework Statement Starting from rest an airplane lifts off the ground after 40s and 1.8km. What is its speed at takeoff and its average acceleration during the takeoff run? Homework Equations V= distance/time Acceleration= (Vf-Vi)/time The Attempt at a Solution The airplane travels 1.8km in...
19. ### Find average acceleration - vectors

1. A car is traveling 9m/s Northwest. 8 seconds later it has rounded a corner and is now heading North at 15m/s. This was a question from my textbook and was an example question - so they supplied answers. I was able to work through all of it finding everything except the last question. They...
20. ### Finding the average acceleration of a basketball player

Homework Statement A bascketball player , who has a weight of 890 N , jumps vertically with a height of 1.2 m , 1- Find his speed when he left the floor. 2- If the time that takes the basketball player to quit the floor is 0.3 s, what is his average acceleration ? (I don't understand this...
21. ### Average acceleration of the a particle in circular motion

Homework Statement A particle of mass ##m## moves along a circle of radius ##R##. The modulus of the average vector of the force acting on the particle over the distance equal to a quarter of the circle is: zero if the particle moves with uniform speed ##v##. ##\dfrac{\sqrt2mv^2}{\pi R}## if...
22. ### Angle of average acceleration while turning a curve

Homework Statement A cyclist is initially heading exactly due North. He then initiates a turn to the West, the turn being a quarter circle with radius 12-m. He travels at a constant speed of 5.5-m/s during the turn. What is the direction of this average acceleration, measured anti-clockwise...
23. ### Average acceleration and total acceleration of gravity

Say you have a gravitational acceleration between a spherical object of mass M and inner radius R and a much smaller spherical object of mass m (essentially point-like) and distance ro away (M >> m) with an acceleration on mass m at any point r given by a = GM/r2 Knowing that the acceleration...
24. ### MHB Average Acceleration problem

I would just appreciate someone checking this please, I'm not sure of my answer ... Q: Car moves North with constant speed 50 mph for 5 mins. It then turns 45 degree east and continues at 55 mph for 1 min. Find ave. acceleration. For x, y components, Cos45 = Sin45 = 0.7, so for the 2nd part...
25. ### Average Acceleration and Speed

Homework Statement You are driving down a highway at a speed of 25.0 mph when your car accelerates at 55 mph in order to pass another car. What is the average acceleration of this car if this increase in speed occurs over a time period of 5.00 seconds? t = 5 seconds initial speed = 25.0 mph...
26. ### Direction and Average Acceleration

You and your little brother are rolling toy cars back and forth to each other across the floor. He is sitting at x = 0, and you are at x = 4.0 m. You roll a car toward him, giving it an initial speed of 2.2 m/s . It stops just as it reaches him in 3.0 s. In what direction is the car's...
27. ### Average acceleration of impact of ball.

A ball travels vertically downwards until it hits a concrete floor with speed 16.1-m/s. It then bounces vertically upwards at 3.4-m/s. Examination of a high speed video shows that the collision took 1.1-ms. Considering just the collision, what is the magnitude of the average acceleration? b)...
28. ### Determining average acceleration during point of impact

Homework Statement Hello, new to the physics world, I am trying to self-teach through reading textbooks, videos etc and application. I came across a problem I do not know how to begin to answer. A dodgem car of mass 200g is driven due south into a rigid barrier at an initial speed of 5.0...
29. ### Conceptual issue with average acceleration problem in Giancoli

Hi all, I recently came upon the following problem in Giancoli's Physics Principles With Applications, 6th ed. textbook that I am having some issues understanding. I am new here, so I do apologize if I have made any mistakes in formatting or anything else. Homework Statement A 0.140-kg...
30. ### Average Acceleration Question

Homework Statement A motorboat traveling in a straight line has a velocity of +4.0 m/s at some point in time. After 5.0 seconds, its velocity is +7.0 m/s. What is its average acceleration during this time?Homework Equations avg accel.=change in velocity/change in time The Attempt at a...
31. ### Bad Question - Average Acceleration

Homework Statement A car starts from rest. With constant acceleration, the car increases its speed from 10m/s to 50m/s over a distance of 60m. How long does this take? Purported answer: 4.0s Homework Equations Constant acceleration, so the following equations apply: Vf^2 = Vi^2...
32. ### Average acceleration formula

The formula for average acceleration is (v_final - v_initial) / (t_initial - t_final), I was wondering if v_initial and _final are the instantaneous velocities (found by second derivative of a function) at those points or are they the average velocities (found by change in distance over time)...
33. ### Direction of car's average acceleration vector as it turns

Homework Statement A car, initially going east ward, rounds a 90 degree curve and ends up heading southward. If the speedometer reading remains constant, what's the direction of the car's average acceleration. The Attempt at a Solution a = Δv/Δt vi = (c,0) vf = (0,-c) (vf -...
34. ### Help finding Normal average acceleration of path.

A particle moves along the curved path sown. if the particle has a speed of 40ft/sec at A at time ta and a speed of 44ft/sec at B at time tb, determine the average values of he acceleration of hte particle between A and B, bath normal and tangent to the path. I found the average tangent...
35. ### Force to average acceleration

I know that there is an equation for an accelerating object that is already a notable fraction of the speed of light (force = gamma^3 * mass * acceleration), but gamma is changing while the object accelerates so what i want to know is how to calculate the average acceleration of an object when...
36. ### Average acceleration given three velocity vectors?

Can someone explain this? http://puu.sh/4LNE6.png [Broken] What is the relevance of t1 < t2 < t3
37. ### Average acceleration from average velocity?

Homework Statement A particle travels from point A to point B following a semicircular path (a half-circle) of radius 5 m, and it travels at a constant speed of 1 m/s. Find the average acceleration of the particle. Homework Equations Average acceleration = change in velocity/ change...
38. ### Find average acceleration from two given velocities each at a given ti

The velocity of an object at t=0 seconds is 40 m/s directed due North. The velocity of the same object at t=5 seconds is 30 m/s directed due east. Find the magnitude of the average acceleration of the object over the time interval from t=0 to t=5 seconds. Also, show the direction of the...
39. ### Help with an Average Acceleration question during a time period

If a rugby player is running at 3.69 m/s and then decides to sprint in a straight line for a ball and 3.27 seconds later is running at 7.29 m/s, what is their average acceleration during that time? Units and direction of travel are not required Homework Equations The Attempt at a...
40. ### Average acceleration given velocity points?

How do you find average acceleration given a table with points of velocity (ft/sec)? t (sec): 0 15 30 45 60 v(t) (ft/sec):0 40 60 70 75 the question asks: Find the average acceleration of Rocket A over t=[0,60] seconds. I used change in v(t)/change in time to find 4...
41. ### Average Acceleration of a golf swing

Hello, I'm actually working on a project, which record the acceleration of a golf club via an accelerometer. And with the data of it i have manage to draw a graphic of a golf swing. My question is : how can i get the average speed of the recorded data. Indication, the time is in ms.
42. ### Average acceleration and average force

Homework Statement Steel ball with a mass 17 grams, is launched at a speed of 6 m/s, into someones eye. The ball comes to a rest over a distance of 1mm. A) What is the average acceleration experienced by the ball to stop it? B) What is the deaccelerating force that must be exerted on...
43. ### Kinematics: finding the average acceleration

1. Homework Statement The velocity of a particle moving along the x-axis varies in time according to the expression v(t)=α+βt2 α=46.4m/s β=4.25m/s3 t is in seconds Find the average acceleration in the time interval from t=0 to 3.63s. Answer in units of m/s2 2. Homework...
44. ### Average Acceleration of a Accel vs Speed Graph

Hi All So I have an Accel vs Speed graph and data. Goes from 0 to 80 mph. This is all the info I have. I would like to figure out what Average Acceleration would give me the same distance, of an acceleration from 0 MPH to 80 MPH. AKA, using the formula Distance =...
45. ### Finding average acceleration with two sets of velocity vecotors

Homework Statement A jet plane is flying at a constant altitude. At time t1=0 it has components of velocity vx=95m/s, vy=115m/s. At time t2=33s the components are vx=172m/s, vy=35m/s. Find average acceleration. Homework Equations avg acceleration=vfinal-vinitial/change in time The...
46. ### Need Help with an Average Acceleration Problem

A car traveling with a constant speed of 14 m/s due west comes to an intersection where it makes a turn onto a southwest (45 degree) street. The car takes 5.2 seconds to complete the turn and the speed of the car does not change during this time. Find the average acceleration of the car. Report...
47. ### Free Fall Lab Question: Calculating Average Acceleration and Velocity

Homework Statement Within this lab I was supposed to perform a virtual experiment and find the rate a ball dropped on the moon, mars, and earth. I have recorded all of my results in the table below. My problem is that my average velocity on Earth ended up as 8.9 m/s, and I thought that the...
48. ### Derive 1-dimensional motion from average acceleration (no calculus)

Starting with the expressions for average acceleration (Change in Velocity over Change in time), average velocity at constant acceleration; algebraically (NO CALCULUS) derive the equation for one-dimensional motion that relates displacement to the acceleration, assuming acceleration is constant.
49. ### Finding Average Acceleration

Homework Statement Here's the graph: http://i.imgur.com/uUXPO.jpg What is the average acceleration between t=0s and t=2s? Homework Equations a avg = change in velocity / change in time ; (Vf-Vi)/(tf-ti) The Attempt at a Solution I know how to solve it if it was just a straight line where I...
50. ### Finding Average Acceleration

A 45.0-g Super Ball traveling at 30.0 m/s bounces off a brick wall and rebounds at 20.5 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.70 ms, what is the magnitude of the average acceleration of the ball during this time interval? Apparently the...