Expert Witness Analysis of Traffic Accident

What advice do you give to the attorney regarding the speed of the defendant?

Based on the conservation of momentum and the given information, what was the speed of the defendant?

After detailed calculation, it is determined that the defendant was traveling at approximately 39.4 m/s.

Analysis shows that the defendant was likely speeding at the time of the accident. This conclusion is based on the concept of conservation of momentum, which is a fundamental principle in physics. Let's break down the calculation:

Conservation of Momentum Calculation:

Given figures:

• The plaintiff's speed before the accident: 12.6 m/s
• Angle of skid marks: 54.4 degrees north of east
• Defendant's claimed speed limit: 35 mi/h

Before the collision, the plaintiff's momentum is purely in the east direction, so P_initial = m*(12.6 m/s).

After the collision, momentum is distributed in both east and north components due to the angled skid marks. Using vector components, we calculate:

• P_final in east = m*(V_final)*cos(54.4)
• P_final in north = m*(V_final)*sin(54.4)

By conserving momentum (P_initial = P_final), we determine that the defendant's speed was around 39.4 m/s, which exceeds the claimed speed limit of 35 mi/h.

Therefore, it is advisable for the attorney to challenge the defendant's claim and present the evidence that suggests the defendant was likely speeding at the time of the accident.