Calculating acceleration from 2 tangent lines

In summary, the conversation discusses the use of a position vs. time graph to find acceleration. The speaker mentions finding the slope of two tangent lines, which represent velocity, and their values of 295cm/s and 575cm/s. The question is then raised about how to calculate acceleration using these slopes. The solution is given to not use final time in the acceleration equation and that acceleration can be calculated over any time interval if it is constant.
  • #1
azn4lyf89
17
0
I have a position vs. time graph which is slightly curved. I found the slope of 2 tangent lines which I know are the velocity. My question is how do I get the acceleration using these 2 slopes. One slope is 295cm/s and the other is 575cm/s. I know that avg acceleration is final velocity - initial velocity/ final time - initial time but because these points aren't at the initial and final times, I don't think I can use that.
 
Physics news on Phys.org
  • #2
Then don't use final time in the acceleration equation! If acceleration is a constant, you can calculate it over any time interval.
 
  • #3


To calculate the acceleration from these two tangent lines, you can use the formula for instantaneous acceleration, which is the derivative of velocity with respect to time. In other words, you can find the change in velocity (575cm/s - 295cm/s = 280cm/s) and divide it by the change in time between the two points on the graph. This will give you the instantaneous acceleration at that specific point on the graph.

However, if you want to find the average acceleration over a longer period of time, you can use the formula you mentioned: average acceleration = (final velocity - initial velocity) / (final time - initial time). In this case, you will need to choose two points on the graph that are closer to the initial and final times, and use the corresponding velocities and times to calculate the average acceleration.

It's important to note that the instantaneous acceleration at a specific point on the graph may be different from the average acceleration over a longer period of time, since the velocity and acceleration may be changing continuously. It may also be helpful to plot the data points and calculate the slope of the line connecting them to get a more accurate estimate of the acceleration.
 

Related to Calculating acceleration from 2 tangent lines

1. How do you calculate acceleration from 2 tangent lines?

To calculate acceleration from 2 tangent lines, you need to first determine the slope of each line. Then, subtract the initial velocity from the final velocity and divide by the time interval between the two tangent points.

2. What is the difference between average acceleration and instantaneous acceleration?

Average acceleration is the overall change in velocity over a given time period, while instantaneous acceleration is the acceleration at a specific moment in time.

3. Can you calculate acceleration without knowing the initial velocity?

No, you need to know the initial velocity in order to calculate acceleration using two tangent lines. However, if you have the distance and time data, you can use the formula a = (v^2 - u^2)/2d to calculate acceleration without knowing the initial velocity.

4. How do you represent acceleration on a velocity-time graph?

Acceleration is represented by the slope of the line on a velocity-time graph. A steeper slope indicates a greater acceleration, while a flatter slope indicates a slower acceleration.

5. What is the unit of measurement for acceleration?

The unit of measurement for acceleration is meters per second squared (m/s^2).

Similar threads

  • Introductory Physics Homework Help
Replies
9
Views
292
  • Introductory Physics Homework Help
Replies
13
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
4K
  • Introductory Physics Homework Help
Replies
3
Views
842
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
17
Views
1K
  • Introductory Physics Homework Help
Replies
13
Views
823
  • Introductory Physics Homework Help
3
Replies
98
Views
4K
  • Introductory Physics Homework Help
Replies
17
Views
2K
  • Introductory Physics Homework Help
Replies
13
Views
2K
Back
Top