College Physics with MasteringPhysics 7th Edition by Jerry Wilson,Anthony Buffa,Bo Lou

Exercise 79

An automobile is traveling on a long, straight highway at a steady 75.0 mi/h when the driver sees a wreck 150 m ahead. At that instant, she applies the brakes (ignore reaction time). Between her and the wreck are two different surfaces. First there is 100 m of ice, where the deceleration is only 1.00 m/s 2. From then on, it is dry concrete, where the deceleration is a more normal 7.00 m/s 2. (a) What was the car's speed just after leaving the icy portion of the road (b) What is the total distance her car travels before it comes to a stop (c) What is the total time it took the car to stop