Velocity versus time form acceleration versus time

Click For Summary

Homework Help Overview

The discussion revolves around converting acceleration data collected from a lab experiment into a velocity versus time graph. The original poster presents a challenge in visualizing the acceleration data, which varies significantly over time, and seeks to understand the relationship between the two graphs.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the method of integrating acceleration to find velocity, with some suggesting a discrete summation approach due to the nature of the data. Questions arise regarding the application of kinematic equations for position calculation based on the derived velocity.

Discussion Status

The conversation is ongoing, with participants exploring different methods for calculating velocity from acceleration data. Some guidance has been provided regarding the use of discrete sums and kinematic equations, but no consensus has been reached on the best approach.

Contextual Notes

The original poster has specific data points at intervals of 0.1 seconds and is working within the constraints of this experimental setup. There is an acknowledgment of the complexity of the acceleration data, which affects the graphing process.

KillerZ
Messages
116
Reaction score
0

Homework Statement



I have some data from a lab conducted with a accelerometer to collect the acceleration and I am trying to figure out how to create a v vs t graph from the a vs t graph. When I create the a vs t graph in excel its very crazy looking because of the change in acceleration at every 0.1 s from 0 s to 79.6 s. I know the v vs t is constructed from the area under the a vs t graph. The speed of the object is 0 km/h to 40 km/h = 0 m/s to 11.1111 m/s. I have every point of the instantaneous acceleration at every 0.1 s.

my a vs t graph:
14tydsj.png


my acceleration data looks like this from 0 s to 79.6 s:
avsz1s.jpg


Homework Equations



\Delta v = \int a dt

The Attempt at a Solution



well I know the time is 0 s to 79.6 s and the velocity is 0 m/s to 11.1111 m/s so I think I can integrate?

\Delta v = \int a dt
 
Physics news on Phys.org
Integration is actually a discrete sum in this case. You don't have an analytical function that you can integrate. Just multiply the acceleration at a given point in time by the time interval Δt = 0.1 s and call that Δv. Add all the Δv's from time zero to the time of interest to get the velocity at the time of interest.
 
I used this formula:

v_{n} = v_{n-1} + a_{n}(0.1)

which is what you said but would the position be:

x_{n} = x_{n-1} + v_{n-1}(0.1) + (0.5)a_{n}(0.1)^{2}

y_{n} = y_{n-1} + v_{n-1}(0.1) + (0.5)a_{n}(0.1)^{2}

for every point?
 
It will (probably) be better to use the "other kinematic equation"

<br /> \Delta x_{n} = \frac{v_{n}^2-v_{n-1}^2}{2a_{n}}<br />
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
1K
Replies
7
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
1
Views
3K
  • · Replies 10 ·
Replies
10
Views
1K
Replies
7
Views
3K