# Thread: Average and Instantaneous Acceleration (physics)

1. ## Average and Instantaneous Acceleration (physics)

Hey guys…I got an assignment from our physics class and I was having a hard time answering this problem . Maybe if you could lend me some of your helps and of coarse it would mean a lot to me.

Here’s the problem:

“A test driver at incredible motors. Inc, is testing a new model car with a speedometer calibrated to read m/s rather than mi/h. The following series of speedometer readings was obtained during a test run along a long, straight road:”

 TIME (s) 0 2 4 6 8 10 12 14 16 SPEED (m/s) 0 0 2 6 10 16 19 22 22

by the way this problem was taken in the book of Young and Freedman "THE UNIVERSITY OF PHYSICS"
I am hoping that you guys can help me with this

2. ## Re: Average and Instantaneous Acceleration (physics)

Originally Posted by REDnight
Hey guys…I got an assignment from our physics class and I was having a hard time answering this problem . Maybe if you could lend me some of your helps and of coarse it would mean a lot to me.

Here’s the problem:

“A test driver at incredible motors. Inc, is testing a new model car with a speedometer calibrated to read m/s rather than mi/h. The following series of speedometer readings was obtained during a test run along a long, straight road:”

 TIME (s) 0 2 4 6 8 10 12 14 16 SPEED (m/s) 0 0 2 6 10 16 19 22 22

by the way this problem was taken in the book of Young and Freedman "THE UNIVERSITY OF PHYSICS"
I am hoping that you guys can help me with this
What's the question?

3. ## Re: Average and Instantaneous Acceleration (physics)

oh! sorry I forgot to put the question

the question is :

*Compute the average acceleration during each 2-s interval. Is the acceleration constant? Is it sonstant during any part of the test run?
*Make a vᵪ-t graph of the data above , using scales of 1cm=1 s horizontally and 1 cm = 2m/s vertically. Draw a smooth curve through the plotted points. By measuring the slope of your curve, find the instantaneous acceleration at t=9 s, 13 s, and 15 s.

4. ## Re: Average and Instantaneous Acceleration (physics)

Originally Posted by REDnight
oh! sorry I forgot to put the question

the question is :

*Compute the average acceleration during each 2-s interval. Is the acceleration constant? Is it sonstant during any part of the test run?
*Make a vᵪ-t graph of the data above , using scales of 1cm=1 s horizontally and 1 cm = 2m/s vertically. Draw a smooth curve through the plotted points. By measuring the slope of your curve, find the instantaneous acceleration at t=9 s, 13 s, and 15 s.
Number 2 is trivial, it's just plotting points on a piece of paper, then, as the man says, measuring the slope of the curve.

Number 1: $\frac {v_{n+1} - v_n} {t_{n+1} - t_n}$ where $v_k$ is the speed at time point $t_k$. Of course $t_{n+1} - t_n$ is in this context always 2.

5. ## Re: Average and Instantaneous Acceleration (physics)

the answer for the: *Compute the average acceleration during each 2-s interval. Is the acceleration constant? Is it sonstant during any part of the test run? is
(in m/s²) 0,1.0,2.0,2.0,3.0,1.5,1.5,0; no; yes

the answer for the *Make a vᵪ-t graph of the data above , using scales of 1cm=1 s horizontally and 1 cm = 2m/s vertically. Draw a smooth curve through the plotted points. By measuring the slope of your curve, find the instantaneous acceleration at t=9 s, 13 s, and 15 s. is
2.5 m/s², 1.5 m/s², 0

6. ## Re: Average and Instantaneous Acceleration (physics)

I'll pm you for the photo (solution for this)

7. ## Re: Average and Instantaneous Acceleration (physics)

Originally Posted by Legolas
I'll pm you for the photo (solution for this)
oh!!ok ..thanks =))

8. ## Re: Average and Instantaneous Acceleration (physics)

Originally Posted by Legolas
the answer for the: *Compute the average acceleration during each 2-s interval. Is the acceleration constant? Is it sonstant during any part of the test run? is
(in m/s²) 0,1.0,2.0,2.0,3.0,1.5,1.5,0; no; yes

the answer for the *Make a vᵪ-t graph of the data above , using scales of 1cm=1 s horizontally and 1 cm = 2m/s vertically. Draw a smooth curve through the plotted points. By measuring the slope of your curve, find the instantaneous acceleration at t=9 s, 13 s, and 15 s. is
2.5 m/s², 1.5 m/s², 0
It's customary, on mathhelpforum, not to provide the full solution in one go, but rather to give the querent hints and a direction in which to go.

This especially applies when someone has already provided a hint and/or partial solution, and the querent has not yet replied to it.

9. ## Re: Average and Instantaneous Acceleration (physics)

Originally Posted by Legolas
I'll pm you for the photo (solution for this)
Another custom is to post help or solutions in the actual thread so others with questions can benefit from it.

And, not to nitpick, please choose a darker color for your text. It's a little hard to see.

-Dan