Calculate the average acceleration of 2 or more objects?

Click For Summary

Discussion Overview

The discussion revolves around the calculation of average acceleration for multiple objects, specifically addressing whether it is appropriate to simply add the accelerations and divide by the number of objects. The context includes considerations of measurement time, dimensionality, and the nature of acceleration in relation to exponential growth.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant questions if they can calculate the average acceleration of three objects by adding their accelerations and dividing by three, given that the measurement times are approximately equal.
  • Another participant suggests that accelerations can be averaged as proposed, but emphasizes the need for a 3-dimensional average, calculating separate averages for each axis (x, y, z).
  • A participant clarifies a misunderstanding regarding logarithms, stating that they meant to refer to exponentials in the context of averaging accelerations from vibration measurements taken from cars.
  • It is noted that constant acceleration leads to linearly increasing velocity and exponentially growing displacement, but accelerations themselves are not exponential.
  • Concerns are raised about the complexities of the experiment, including the need to distinguish between the accelerations of the driver and the vehicle, and the importance of using a consistent coordinate system, particularly an inertial frame of reference.
  • A request for more details about the experimental setup is made to better assist with the calculations.

Areas of Agreement / Disagreement

Participants express differing views on the appropriateness of averaging accelerations directly and the implications of exponential growth in relation to acceleration. The discussion remains unresolved regarding the best method for calculating average acceleration in this context.

Contextual Notes

Participants highlight the need for clarity regarding the experimental setup, including the placement of sensors and the specific conditions under which measurements were taken. There is an acknowledgment of the potential complications arising from different types of acceleration and the coordinate system used.

mrmazw
Messages
3
Reaction score
0
can i take calc. the average acceleration (m/s2) of 3 objects by adding them and dividing the answer by 3 if the measuretime is more or less equal for the 3 objects? or what should i do different?
do you not have to take into account that you are adding and dividing logarithms? and can you do it with any number of objects?
 
Physics news on Phys.org
mrmazw said:
can i take calc. the average acceleration (m/s2) of 3 objects by adding them and dividing the answer by 3 if the measuretime is more or less equal for the 3 objects? or what should i do different?
do you not have to take into account that you are adding and dividing logarithms? and can you do it with any number of objects?

What do you mean by logarithms? Accelerations can be averaged as you say. You will want to do a 3-dimensional average, in general, so calculate the 3 averages (one in each of the x, y and z dimensions, for example).
 
berkeman said:
What do you mean by logarithms? Accelerations can be averaged as you say. You will want to do a 3-dimensional average, in general, so calculate the 3 averages (one in each of the x, y and z dimensions, for example).

Thank you Berkeman, I made a mistake and meant exponentials. I took several vibration measurements of persons driving cars. Due to the amount of unavoidable variables I wanted to average the x,y,z directions (separately for each of the axis of course) for each of the multiple measurements taken per person. Because acceleration means exponential growth, I thought I could not add them and divide them by the number of measurements, can I?
 
mrmazw said:
Thank you Berkeman, I made a mistake and meant exponentials. I took several vibration measurements of persons driving cars. Due to the amount of unavoidable variables I wanted to average the x,y,z directions (separately for each of the axis of course) for each of the multiple measurements taken per person. Because acceleration means exponential growth, I thought I could not add them and divide them by the number of measurements, can I?

A constant acceleration results in a linearly increasing velocity, and an exponentially growing displacement. The accelerations are not exponential in themselves.

I'm not understanding what your experiment was, so it's hard for me to give you a firm answer about how to do the math. You also have to be careful about acceleratsions of the drivers and accelerations of the vehicle, and be consistent about what coordinate system you are using. You probably need to use an inertial frame of reference, which would not be the car if it is accelerating or going in a circle.

I guess if you could post a diagram or more clearly state where the sensors were and what the vehicle and driver were doing, we would have a better chance at guiding your calculations.
 
many thanks for your assistance, it is already very helpfull. if i run into problems with the calc. I will add them to this threat later. thank you
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 22 ·
Replies
22
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 15 ·
Replies
15
Views
5K
  • · Replies 17 ·
Replies
17
Views
2K