3. At a certain moment, a car travelling at 40mph begins braking for a railroad crossing. Assume that the acceleration is constant (and negative!) and that 2 minutes later, the car comes to a stop, just before the crossing. (a) Find a formula for the velocity v(t) at any moment during the deceleration. (Hint: use units in terms of hours, and use (10 in Section 5.4.) (b) Determine how far away from the railroad crossing the car was when it began decelerating. (Hint: (9) in Section 5.4 should help.)

3. At a certain moment, a car travelling at 40mph begins braking for a railroad crossing. Assume that the acceleration is constant (and negative!) and that 2 minutes later, the car comes to a stop, just before the crossing. (a) Find a formula for the velocity v(t) at any moment during the deceleration. (Hint: use units in terms of hours, and use (10 in Section 5.4.) (b) Determine how far away from the railroad crossing the car was when it began decelerating. (Hint: (9) in Section 5.4 should help.)

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter2: Motion In One Dimension

Section: Chapter Questions

Problem 49P: Traumatic brain injury such as concussion results when the head undergoes a very large acceleration....

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