The Traffic Accident Reconstruction Origin -Approach Angles Problem-
This collision involves two vehicles, red and blue. The red vehicle was eastbound when due to mechanical reason its driver stopped in the middle lane. The blue vehicle was also eastbound at an unknown speed. The driver of the blue vehicle recognized the red vehicle as a hazard and locked his brakes just about the time the two vehicles struck. The driver of the red vehicle saw the blue vehicle coming. Knowing he was about to be involved in a collision he stepped on the brake pedal. As a result each vehicle left four skid marks from impact to rest. Both vehicles remained in contact. Both vehicles skidded 66 feet (20 m). The drag factor on the roadway was 0.65. The grade was insignificant. The weight of the blue vehicle was 3000lbs (1360kg). The red vehicle weighed 4000 lbs (1814kg) as indicated in Figure 1.
This collision involved the same vehicles, red and blue, in the same location as collision 1. As in collision 1 the red vehicle stalls in traffic, but this time the vehicle is pointed north . As before, the blue vehicle is approaching eastbound. The driver of the blue vehicle recognizes the hazard just as the vehicles make contact. He locks his brakes. As in collision 1 both vehicles remain engaged and skid all tires to rest. This collision is diagrammed in Figure 2.
1) In collision 1 the pre collision speed of the red vehicle was 0. What was the pre collision speed of the blue vehicle?
2) In collision 2 the pre collision speed of the red vehicle was 0. What was the pre collision speed of the blue vehicle?
3) What is the Delta-V (velocity change) for each vehcile in collision 1?
4) What is the Delta-V (velocity change) for each vehcile in collision 2?
5) Is the Delta-V (velocity change) different for the red vehicle in collision 1 and collision 2?
6) Would we expect the driver of the red vehicles injuries to be better, the same, or worse in collision 2 when compared to collision 1?
There is no further information.
A solution by Dan Kemble