Was Either Car Speeding at the Time of the Accident?

[High_Voltage]

Homework Statement

You arrive at the scene of an automobile accident and are asked to determine which, if any, of the cars was speeding. You immediately begin gathering information. The accident occurred on dry concrete and the tires of both cars are made of rubber. The coefficient of kinetic friction is .68. The first car, a 2006 Cadillac Escapade, approached from the North while the other, a 2007 Honda Accord Hybrid, approached from the West. The two cars stuck together and produced a skid mark 66 degrees South of East (at 294 degrees). The length of the skidmark is 13.9m. According to the manuals inside of the cars, the Honda has a mass of 1640kg while the Cadillac has a mass of 2675kg. Each car in a 30 mile per hour zone at the time of the crash. One mile is equivalent to 1.6km. Should either driver be issued a ticket for speeding?

Homework Equations

p=mv
Vf^2=Vi^2+2ad
Ffk= µ x Fn

The Attempt at a Solution

28755.16 Newtons / 4315kg = 6.664m/s^2

Vf^2=Vi^2+2ad
0^2=Vi^2+2(6.664)(13.9)
Vi=13.61m/s

 

[D H]

Good so far. What do you think that speed of 13.61 m/s represents?

What is the next step?