Practice Test Flashcards
If weight is measured in pounds and velocity in mph, what are the units of momentum?
Lbs - mph
When measuring the departure angle of a vehicle for use in conservation of momentum analysis, the angle would best be determined by?
Extending a line from th CM at maximum engagement to separation
The speed change a vehicle experiences in a typical two car collision can be estimated from?
The damage the vehicle sustains
The three elements during the “at-crash” phase of a collision are?
Initial contact
Maximum engagement
Separation
To determine the post impact declaration distance of a vehicle involved in a collision, you should?
Measure the CM path of travel from point of separation to POR
A critical factor in analyzing what type of trajectory path was in a pedestrian versus mid-sized auto collision would be?
Height of the pedestrian
What is the least common trajectory for a pedestrian involved in an auto–pedestrian collision?
Somersault
In what type of auto-pedestrian collision would you expect to see speed match-up to MOST likely occur?
Forward projection
In sudden decompression, shear forces are transmitted to the aorta which usually produces ruptures at the?
Fixation sights
In a motorcycle versus vehicle collision in which the rider and passenger are cleanly ejected from the motorcycle, which of the following are true?
The passenger will normally travel farther than the rider
Countrecoupe injury is a type of contusion or laceration which occurs when the head is?
In motion
Head-on collisions usually transmit _________________ loading forces to the femoral shaft.
Axial
Dicing or stellar lacerations are produced by impacts with?
Tempered glass side windows
When measuring entry and depature angles for the calculation of velocity using the General Conservation of Momentum Solution Technique, the angles must be measured _________.
Counter clockwise from the positive x-axis
A shallow entry angle collision in which the entry angle between the two vehicles is __________.
Less than 10 degrees
A standard downsliding motorcycle (no fairings or crash bars) will generate a drag factor range of _____ to _____ on a concrete or asphalt surface.
.5 to .7
Which of the following is NOT a condition for using Severy method of determining speed from the damage a motorcycle sustains in a collision?
The vehicle struck should be moving with respect to the motorcylce
The normal range of drag factors for a pedestrian or motorcyclist rolling, tumbling, and sliding on a paved surface is __________.
.8 to 1.2
In a collision between two vehicles of similar weight, one vehicle sustains greater damage than the other. The likely reason for the difference in damage would be __________.
The strength of the vehicle structure impacted
To determine if inhaled carbon monoxide (CO) is a factor in a fatal crash, a __________ test should be requested.
Carboxyhemoglobin
One reason for the reduced drag factor on large trucks when compared to a passenger car drag factor is __________.
Truck Tire compounds are harder
When only the trailer axle of a truck-tractor and semi-trailer combination lock up, the rig should ________.
Experience trailer swing
During a jackknife scenario, the trailer of a truck-tractor and semi-trailer combination will __________.
Push from behind towards the articulation point thus accentuating the tractor yaw
Horne’s thesis on jackknifing accidents generally states that __________.
Empty or light loaded combinations on wet surfaces are more prone to suffer jackknife collisions than loaded combinations
Air brake lag time is one reason for __________.
Decreased drag factors for large trucks
Which factor does not affect the rollover threshold on a large tractor semi-trailer combination
Brakes
Off tracking in larhe vehicle combinations refers to _________.
Movement of the rear trailer axle in reference to the front steer axle
The abbreviation “CRASH” stands for ________.
CALSPAN Reconstruction of Accident Speeds on the Highway
When using the CRASH 3 computer program, the PDOF’s must be collinear within __________.
15 degrees
According to measuring protocol, induced damage should not be included in the measurement of the length of the damage region when __________.
It is in the form of buckling in the roof or side panels and is remote from the contact or direct damage
&
It is superficial contact without displacement
Crush measurements for the change in velocity should NORMALLY be taken at _________.
The bumper-frame level
When adjusting crush measurements for use with CRASH 3 energy equations, you adjust for bowing greater than 4 inches in SIDE IMPACTS by _________.
Adding the bowing constant to your field crush measurements
For momentum to be conserved in a collision system, the following must be true:
No external forces are acting on the system
The equation shown is derived for use in what type of collision?
Need equation
Central
In a large truck versus car collisions, which of the following would be a reason why conservation of momentum should NOT be used to calculate the impact speed of the smaller vehicle?
The entry and exit angles of the vehicles normally CANNOT be determined with enough accuracy to ensure accurate speed calculation of the smaller vehicle
Another name for Cartsian coordinate system is __________.
Orthogonal coordinate system
The basic definition of the sine of the central angle in a right triangle is which of the following?
The ratio of the side opposite the central angle to the hypotenuse
A vector quantity is a quantity that requires _________.
Magnitude and direction
Force is ________.
A vector quantity
A collision which has a coefficient of restitution of zero, and in which kinetic energy is not conserved, is an example of what kind of collision?
Inelastic
