Wu Wen saw Sima Qiqi with a puzzled face, Wu Wen was interested at this time, and said with his hands dancing: "Let me explain to you, if the car collides with the guardrail at a vertical angle or an angle close to 90 degrees, then the guardrail will be damaged but the vehicle will not break the bridge guardrail, but when the car collides with the guardrail at the same speed but at an angle of 20~40 degrees, then the guardrail will be broken." ”

Hearing this, he almost rolled his eyes, and hurriedly interrupted Wu Wen: "No, the impact force of hitting at a vertical angle is great, why does a frontal collision not smash the guardrail, but a certain angle collides with the guardrail but will smash the guardrail?" ”

Wu Wen heard this question, and said excitedly "Goodquestion", seeing that Wu Wen was like a lecture at this time, enthusiastic, only to hear Wu Wen say excitedly: "Bridge guardrail don't think it's the same as a cement wall, it is a building elastic material, when the vehicle collides with the guardrail, the guardrail will change elastically at a speed that is imperceptible to the naked eye, and the impact force will be dispersed by internal and external shaking, so when the car collides with the guardrail at a near-vertical angle, the guardrail can disperse most of the force, However, in this case, the car collided with the guardrail at an angle of 35 degrees, and the force was divided into vertical and horizontal directions, and the vertical force could be dispersed by the elastic change of the guardrail, but the force that was horizontal to the guardrail would be transmitted along the guardrail, thereby destroying the inside of the guardrail and destroying the guardrail. ”

Seeing the frequent nodding, Wu Wen didn't forget to ask, "Understood", and when Wu Wen asked like this, he felt embarrassed for a while and didn't know how to answer.

After being stunned for a while, he suddenly thought of something, and asked Wu Wen with a smile: "Eh, but there is still a problem, you said that the driver may have stepped on the brakes but the vehicle did not stop because the bump on the sidewalk caused the vehicle's brakes to temporarily fail." ”

Wu Wen nodded, and then the experimenter also reacted and said: "Yes, in this case, even if the female deceased didn't know that the brakes failed, she was also stepping on the brakes, so the speed of the car should be reduced, but after the car rushed onto the sidewalk, not only did it not slow down, but the speed also increased." ”

also looked at Wu Wen, expecting Wu Wen to give an answer, at this time Sima Qiqi suddenly spoke: "More than this question, I want to ask why this car is still driving very smoothly when it gets on the bridge, and it didn't take long for a sharp turn to occur?" At this time, the three of them discussed nonsense, and Wu Wen felt that his head was about to explode in the middle, so the three of them quickly quieted down.

Wu Wen took off his glasses and wiped them, put them back on and said slowly: "One question at a time, first answer the question of the vehicle making a sharp turn, it is very likely that the contact force between the tires on both sides of the vehicle and the ground is different, and the driver on the car turns the steering wheel in a panic, at this time the vehicle is not the same as the friction between the tires on both sides and the ground, and the driver does not firmly reverse the disk, and then the vehicle will make a sharp turn." ”

He clapped his hands and said, "Oh, I know what you're talking about, it's like there's water on the road, and if you drive over, the car will skid, and if you turn the steering wheel, the vehicle will spin."

A sharp turn will occur. ”

Wu Wen nodded, thought for a while and said, "No, there hasn't even been a wind in Shuzhong City recently, where does the water come from?" ”

Wu Wen smiled bitterly and said: "So I didn't say it was stagnant water just now, I only said that the friction between the tires on both sides of the vehicle and the ground is different." It could be water or other fluids that are slipping the tire, it could be something hard, or it could be that one side of the tire tread is not as deep as the other. ”

Seeing that the three of them stopped talking, Wu Wen suddenly said: "In short, if you want to know what the reason is, you need to look at the vehicle that caused the accident." ”

Hearing Wu Wen say this, he reached out and touched Wu Wen's forehead, and said with a disdainful expression: "There's nothing wrong with you, you want to see that car, that car I guess burned like a fish skeleton, can you still find evidence from that car?" ”

Wu Wen shook his head and said: "The car must have been burned, but the tires should be fine, the vehicle fire is generally burned on the body, and there is not much damage to the tires, so just look at the tires to know what the car rolled at that time, and it will take a sharp turn." Nodding, Sima Qiqi asked, "Then why did the vehicle rush onto the sidewalk and suddenly accelerate?" ”

Wu Wen didn't seem to think of this contradiction, the experimenter held his chin and nodded: "Yes, if the accident vehicle is a manual transmission, it can also be said that the deceased used the clutch as a brake, but the speed of the car did not slow down in the past, but this accident car is an automatic transmission, and there is no clutch, stepping on the brake and the accelerator is the same foot, how can the car still accelerate when stepping on the brake, so strange." ”

Saying that, he looked at Wu Wen, and Sima Qiqi also stared at Wu Wen in anticipation that Wu Wen gave a reasonable explanation.

A week later, Wu Wen used his personal connections to request the Ministry of Transportation to send the accident vehicle to Southwest College of Arts and Sciences. Wu Wen called and told him that he could go to Southwest College of Arts and Sciences to see the results, and hurriedly called Sima Qiqi to fly to Southwest College of Arts and Sciences. When he came to the laboratory where Wu Wen was, as soon as he walked in, Wu Wen greeted the two of them very happily.

Seeing the blackened skeleton of the vehicle behind Wu Wen, he said in surprise: "Brother Wu Wen, I really admire you, you really got this car that was burned to the point that only the skeleton of a fish remains?" ”

Wu Wen said with a smile: "Of course, my face is still sold by others, just right, this car was sent to prepare for decomposition and inspection, let's take a look." ”

After speaking, Wu Wen handed goggles, gloves, shoe covers, and an experimental white coat to Sima Qiqi.

The two of them dressed up and came to the car, watched a few experimenters carefully observe the blackened car, and then reached out and knocked on the blackened car in front of them, and said disdainfully while knocking: "This piece of black charcoal, you are still looking at it so carefully, this car is burned like this, what other clues can you find?" ”

Several experimenters stared, ignoring everyone's gaze, and continued to knock, when the bumper of the car suddenly fell off, leaving powder and black marks on the ground

Remember.

Everyone was frightened by this sudden sound, and then smiled very embarrassedly, squatted down and picked up the bumper and put it on the body of the car and said helplessly: "I'm sorry, everyone, the accident, I didn't know that this bumper fell so easily, it should be the manufacturer of this car who cut corners, I'm sorry, I'm sorry, you guys go and get busy!" ”

Sima Qiqi shook his head and dragged it back, Sima Qiqi smiled politely and said to Wu Wen: "Professor Wu, please start working, don't worry, I will never let you get in the way of your work." ”

As he spoke, he gritted his teeth and glared at Sima Qiqi like this, like a child who had made a mistake, lowered his head and stopped talking.

Wu Wen covered his mouth and laughed when he saw Sima Qiqi and these two people. After laughing for a while, several experimenters began to decompose the car in front of them, and even took out the four tires separately. Several experimenters used scissors to cut off a piece of rubber from each of the four tires and put it in a glass dish. At this time, seeing that the outer frame of the car had been completely disassembled, Wu Wen picked up a pair of lenses and put them in front of his thick glasses, and saw that Wu Wen's eyes were instantly enlarged, and he almost laughed, if it wasn't for Sima Qiqi hitting it with his elbow, he would probably laugh out loud.

Seeing that Wu Wen's head was buried in the position of the front engine, after waiting for a while, Sima Qiqi stood quietly aside and waited for the results of Wu Wen's inspection, he was really impatient, walked to Wu Wen's side and said, "Brother Wu Wen, did you find any evidence?" ”

At this time, I saw Wu Wen raise his head with difficulty, he was still careless, but when he saw Wu Wen's appearance again, he was frightened and retreated, because Wu Wen's face was full of black ash at this time, and the previous glass lenses had also become sunglasses.

Wu Wen took off his glasses and asked the other experimenters to come with a clean flannel cloth to wipe his eyes clean, put them back on and smiled awkwardly and said: "What about this part of the car's engine, it can be said that there is no clue at all, but the cause of the fire should be that the vehicle fell off the bridge, and the front of the car hit the ground first, causing a short circuit in the wires of the engine part of the vehicle, and the oil pipe also caused a crack due to the huge impact force, and the oil overflowed, and the electric spark generated by the short-circuit wire ignited the spilled oil. So the fire burned directly from the front of the car to the fuel tank, so the vehicle was surrounded by fire. ”

Wu Wen said and took Sima Qiqi out of the laboratory to another testing and analysis room, Wu Wen took off the soiled white coat outside the room, and then entered the room, and when he came to the room, Wu Wen asked directly and loudly: "Did you detect any substances on the tires?" ”

An experimenter took out a simple analysis report, which is an ingredient that can be detected immediately with current technology, Wu Wen glanced at it, and then stood behind Wu Wen and stretched his neck and padd his feet to look at the document report in Wu Wen's hand.

Wu Wen turned around and almost collided, seeing that Wu Wen didn't speak for a long time, he snatched the document report and said, "What are you doing without talking for a long time, what is written on this report." ”

Sima Qiqi gradually came over at this time, took the report document and looked at it and said: "There is no useful information on it, oops, I know, the vehicle was on fire at that time, so the fire department used a foam fire extinguisher to extinguish the vehicle, so of course nothing can be found on the tires." It's a real failure, and it's a failure. ”

When Wu Wen heard this, he also patted his head and said to himself: "Yes, why didn't I think of it, I can't find it with liquid, ah, I thought about it." ”

I didn't think about it at first, and said to myself: "What did you think, so excited." ”

Seeing that Wu Wen was very excited, he suddenly realized that he said in unison with Wu Wen: "Use temperament." ”

(End of chapter)