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.
1. What was the potential energy of each car at the beginning of the problem?
2. What was the kinetic energy of each car while it was traveling at its maximum speed?
3. How much energy did Car 1 "lose" from the top to the bottom of the hill, before it began braking? What happened to this lost energy?
4. When Car 1 applied its brakes, how much force did its tires apply to the road to stop?
5. How much power (in watts) did it take to stop Car 1 by applying force to the brakes?
6. What is the momentum of each car right before the accident?
7. What was Car 1's final speed after the accident?