Student’s GuideCollision Investigation (1-D) SPVM File # 990827-32 Camil Cyr Collège de Maisonneuve Adaptation: Nanouk Paré John Abbott College direction vehicles were heading. There has been an accident involving two cars. There are also skid marks over a distance of 30 m before the debris.25 m.Collision Investigation (1-D) SPVM File # 990827-32 Context You are just starting a summer job for Montreal Police (SPVM) collision investigators. as accurately as possible. the circumstances surrounding collisions (initial velocity of the vehicles involved. The weather is great. hurry over to Notre-Dame Street. Your job is to take photos of the vehicles as they are positioned. you rush (although carefully) to the scene of the accident. Other data: m1 = 2. The job is demanding and your help is highly appreciated. m2 = 1. etc. There are people injured. EMBED Word.8 Your findings are as follows: Numerous debris (broken glass.674 kg.25 m from the cars.) in order to take action against drivers at fault under the Criminal Code (dangerous driving causing death or other charges). “Hey. etc. The posted speed limit on this street is 70 km/h.100 kg. You immediately draw the following sketch of the accident and include a few common measurements.” Listening only to your courage. You assist the investigators in order to determine. The two cars stuck together and there are skid marks over 12. plastic. including the length of the skid marks and layout of the debris.) were found at a distance of 12. it’s July. . and take a certain number of measurements.Picture. and you arrive at the station as your boss tells you. Rookie. ” Confused. find an equation that allows you to determine the pavement’s coefficient of friction.1-D Collision Investigation (Part 1) A hurried investigator yells out. make yourself useful! Bring the friction block and spring scale. and the summary. Rookie. what we need to know. Which parameters can be obtained by using the friction block and spring scale? It can give you the value of the Friction between the pavement and the friction block and it also gives you the normal force. Force of Friction = (coefficient of friction)(Normal Force) Complete the three-step cycle to get a clear picture of what we know. covered with tire treads. and take the measurements needed to calculate the pavement’s coefficient of friction. “Hey. and the spring scale. . but very eager. Based on this information about the method used. you take the heavy iron friction block. 8 N and the coefficient of Friction is equal to 0.674 kilograms and the mass of the second car is 1.25 before the collision meters from the cars Summary * *The 2 cars stuck together and there are skid marks over 12.Three-Step Cycle List all the revelant information you have gathered from the problem.plastic.2 N List the following: Please note: You must complete the Part 1 before proceeding to the Part 2. As new information comes in. What we know What we need to know *Numerous debris (broken *We need to know the glass.100 kilograms *The Force of Friction is equal to 75.86 *The Normal Force is equal to 88. . Based on this information. etc. state what you need to know to solve the problem.25 meters *There are also skid marks over a distance of 30 meters before the debris *The posted speed limit on this street is 70 kilometers per hour *The mass of the first car is 2. you will want to summarize and update the relevant information you have gathered and ask new questions.) were velocity of vehicle A and B found at a distance of 12. “Well. of the Criminal Code. based on the skid marks. you take your role very seriously and immediately get to work. The one in the small red car was sent to the hospital. we must be sure. but nothing is clear!” Since you are always willing to help. All I’m sure of is that. that dangerous driving was involved… the judge needs evidence.1-D Collision Investigation (Part 2) Here are the two measurements (Fv: vertical force. They will enable you to determine the pavement’s coefficient of friction.2 N and Fh = 75. what do you suggest to your superior? Press charges for dangerous driving or not? If the Crown prosecutor asked you to testify in court. Considering that the accident occurred in a 70km/h zone. you answer. Dangerous driving causing bodily harm. The driver in the yellow car is still discussing what happened. the red car was at the stop when the collision occurred. beyond any doubt. We must gather all the necessary evidence.8 N The investigator returns to you and says. it’s that…. This a perfect job for an intern! Get to work! I want a full report ASAP”. ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ _______________ . you see. “How can I help you. Knowing that this information will enable the Crown prosecutor to decide whether the driver will be charged under Section 249 (3). Fh: horizontal force) that you obtain from the friction block and spring scale. Sir?” The investigator’s face lights up when he hears your proposition. Fv = 88. how would you clearly explain to the judge and jury the method used to determine the speed of the driver at fault? Prepare a short report of your investigation which will include supporting facts and your recommendation. “The two drivers aren’t saying much. Collision Investigation (1-D) / SPVM File # 990827-32 PAGE \* MERGEFORMAT 5 .PBL/Student’s Guide .