Car Crash Investigation Lab

By: Brandon Perry, Chris Reddick, Tori Piurowski

Accident Scene

Automotive Expert

• A 3500 KG (7716 LB) SUV hit a 2000 KG (4409 LB) Wagon.• The Wagon was parked, and waiting for traffic to clear before

he pulled out.• Using a Physics equation I have determined that at the point

of impact the SUV travelled at a rate of 2.83 Metres per second before coming to a full stop landing only 2 meters away.

• The wagon, after starting out at rest, and then getting hit, travelled at a rate of 12 Metres per second before landing 24 meters away from the impact point.

Collision Expert

• By using the information given from the auto expert, I was able to find the initial velocity of the SUV.

• I used the equation: (m[before 1]v[before 2]) + (m[before 2]v[before 2]) = (m[after 1]v[after 1]) + (m[after 2]v[after 2])

• I then plugged in the numbers: 3000kg(v) + 2000kg(0 km/hr) = 3000kg(2.83 km/hr) + 2000kg(12 km/hr)

• I found that the initial velocity of the SUV was 10.83 m/s

Investigator

• By using the equation KE=1/2mv^2 to find the Kinetic energy of both cars before and after the collision, I was able to determine that the collision was inelastic.

• KE of the wagon before collsion = 0 J. After = 144000 J• KE of SUV before collision = 175933.35 J. After = 12013.35

J.• The collision was not elastic because kinetic energy was not

conserved.• The accident was not perfectly inelastic because the cars

did not stick together.• The collision was inelastic.

The collaborative work of the automotive expert, the collision expert, and the investigator yielded information such as the velocities and kinetic energy of the cars both before and after the collision. This data helped determine that the accident involved an inelastic collision. The speed limit at the scene of the accident was 9.72 m/s, and it was found that the SUV was traveling 10.83 m/s. The SUV was speeding slightly, but not enough to cause such an accident. It is assumed that the driver of the SUV was not paying attention while driving, and his averted attention caused the accident.