Work to stop a car

At an accident scene on a level road, investigators measure a car's skid mark to be 88m long. It was a rainy day and the coefficient of friction was estimated to be 0.42. Use these data to determine the speed of the car when the driver slammed on (and locked) the brakes. (Why does the car's mass not matter?)

Thermal Energy

Two railroad cars, each of mass 6500kg and traveling 95 km/h collide head-on and come to rest. How much thermal energy is produced in this collision?

Mechanical energy problem

A vertical spring (ignore its mass), whose spring constant is 900 N/m, is attached to a table and is compressed 0.150m. What speed can it give to a .300-kg ball wehn released? How high above its original position (spring compression) will the ball fly?

Gravitational potential energy

A baseball is thrown from the roof of a 120 ft tall building with an initial velocity of magnitude 60 ft/s and at an angle of 37 degrees above the horizon. 1. what is the speed of the ball just before it strikes the ground using energy methods? 2. What would be the answer to the first part if the initial velocity was at angle of 37 degrees below the horizon? I tried solving for this by setting kinetic energy 1 (1/2 mv^2) + potential energy 1 (mgy1) = kinetic energy 2 + potential energy 2 (mgy2)but was unable to get the answer of 106 ft/s and need help at least setting this one up.

Biological Evolution contradicted by the 2nd Law of Thermodynamics?

Some people claim that biological evolution violates the second law of thermodynamics, since evolution involves simple life forms developing into more complex, more highly ordered organisms. Why is this argument wrong? I'm pretty sure that the answer lies in the definition of entropy. Doesn't entropy limit itself to energy, not organization? I may be able to do the formulas, but I lack a solid conceptual understanding of entropy and the 2nd law. Thanks for your help