III. Traffic Accident #3:
You have arrived at the final accident scene of the day. Two cars of equal mass (2,000 kg each)
were involved in a head-on accident at a four-way-stop intersection. Here is what you know:
•
Car 1 started at rest and coasted toward the intersection from the top of a 50-meter hill.
.
•
Car 2 was on a flat stretch of road at the bottom of the hill in front of Car 1.
At the bottom of the hill, before braking, Car 1 was going 30 m/s and Car 2 was going 20
m/s.
From the skid marks on the road you can see that Car 1 applied force on its brakes for 5
seconds, 75 meters before the stop sign where it came to a stop.
There were no skid marks left by Car 2. The collision occurred at the stop sign, where Car
1 had stopped. After the collision, Car 2 came to a stop. Car 1's final velocity is unknown.