skid marks and accident reconstruction the skid mark equation n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Skid Marks and Accident Reconstruction – The Skid Mark Equation PowerPoint Presentation
Download Presentation
Skid Marks and Accident Reconstruction – The Skid Mark Equation

Loading in 2 Seconds...

play fullscreen
1 / 12

Skid Marks and Accident Reconstruction – The Skid Mark Equation - PowerPoint PPT Presentation


  • 513 Views
  • Uploaded on

Skid Marks and Accident Reconstruction – The Skid Mark Equation. Officer S. Chavarria #513 Chandler Police Department 602-565-8721. LG#5: Demonstrate VELOCITY and SPEED as a rate of CHANGE OF POSITION OVER TIME Slamming on the brakes locks your brakes. What forces create a skid mark.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Skid Marks and Accident Reconstruction – The Skid Mark Equation' - rahim-velazquez


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
skid marks and accident reconstruction the skid mark equation

Skid Marks and Accident Reconstruction – The Skid Mark Equation

Officer S. Chavarria #513

Chandler Police Department

602-565-8721

slide2

LG#5: Demonstrate VELOCITY and SPEED as a rate of CHANGE OF POSITION OVER TIMESlamming on the brakes locks your brakes. What forces create a skid mark

skid length
Skid length
  • Determines the speed the vehicle was traveling
  • Determine who was at fault or if traffic violations occurred
estimate speed
ESTIMATE SPEED
  • To estimate speed when brakes were applied you will need the following:
  • Measure the skid marks
  • Estimate drag coefficient
  • Determine braking efficiency
what do you need
WHAT DO YOU NEED?

S1: SPEED

d1: Average

Distance

of Skid

Marks

f: Drag

Coefficient

step 1
STEP 1
  • Measure the skid marks
  • If there are several measure all of them
step 2
STEP 2
  • Find the average of the distances by adding each skid and dividing the total by the number of skid marks
step 3
STEP 3
  • Estimate the drag coefficient based on the surface on which the car was driving
  • The drag coefficient represents how much the road contributes to the stopping car
    • The lower drag coefficients represent slicker roads.
step 3 cont
STEP 3 (cont.)
  • EXAMPLES OF DRAG FACTORS:
    • Asphalt: 0.50 to 0.90
    • Gravel: 0.40 to 0.80
    • Ice: 0.10 to 0.25
    • Snow: 0.10 to 0.55
step 4
STEP 4

Estimate the speed by taking the square root of the product of 30 times the average skid distance times the drag coefficient

slide11

Measurements must be taken in feet

  • Skid marks from a vehicle with anti-lock brakes will leave dashed skid mark but you should still measure from the start of the dashes