Hello,
Can you explain what it means if you have a positive delta-v and the data limitations state this indicates Forward - I guess motion. Does that mean this was a frontal crash or the person rear-ended someone?
Thank you for any response.
QUESTION: Positive Sign on Delta-V
- Bob Anderson
- Posts: 198
- Joined: Fri May 27, 2011 8:13 am
- First Name: Bob
- Last Name: Anderson
- Location: Tempe, AZ
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Re: QUESTION: Positive Sign on Delta-V
Newton's 2nd Law can be expressed as: F = m * delta-v/delta-t
Assuming that mass and delta-t are relatively constant, you can see that Force and delta-V are proportional and have the same sign or polarity.
So, if the forward direction is positive. Then, a positive delta-V corresponds with an impact force directed in the positive direction, which is a rear-end impact.
Conversely, a frontal impact has a negatively directed force, which decreases your speed, or produces a negative delta-V.
The positive x-direction is forward in both SAE and ISO sign conventions, so as far as I am aware, all current EDR reported delta-v's will have this same sign convention.
Assuming that mass and delta-t are relatively constant, you can see that Force and delta-V are proportional and have the same sign or polarity.
So, if the forward direction is positive. Then, a positive delta-V corresponds with an impact force directed in the positive direction, which is a rear-end impact.
Conversely, a frontal impact has a negatively directed force, which decreases your speed, or produces a negative delta-V.
The positive x-direction is forward in both SAE and ISO sign conventions, so as far as I am aware, all current EDR reported delta-v's will have this same sign convention.
Bob Anderson
Tempe, Arizona
Tempe, Arizona
Re: QUESTION: Positive Sign on Delta-V
Thank you so much! I appreciate you taking the time greatly.