A Circular Roadway and the Acceleration of Your Car "T (decreasing) (a) Constant angular speed (b) Decreasing angular speed Suppose you are driving a car in a counterclockwise direction on a circular road whose radius is r= 390 m (see Figure 8.20). You look at the speedometer and it reads a steady 32 m/s (about 72 mi/h). (a) What is the angular speed of the car? (b) Determine the acceleration (magnitude and direction) of the car. (c) To avoid a rear-end collision with a vehicle ahead, you apply the brakes and reduce your angular speed to 4.9 x 10-2 rad/s in a time of 4.0 s. What is the tangential acceleration (magnitude and direction) of the car?

Problem 2 A project by some to monitor the traffc safety at a busy intersection. They measwre (with a precision stopwatch) that exactly three seconds after car B passes through the intersection traveling south at vg = 55 mph, minivan A passes through at va = 70 mph on the road that runs at an angle 0 = 60° east of north. The speed of each automobile is Civil Engineering students requires them constant. Determine (a) the relative velocity (in mph) of B with respect to A, draw the vector triangles as part of your answer (b) the change in position (in fi) of B with respect to A during a 10-s interval, (c) the distance (in ft) between the two automobiles 3 s after A has passed through the intersection.

Car A is traveling at a location where the speed limit is 100 km/h. The police officer in car P observes this speed via radar. The driver of car A sees and reacts very unwisely to the police car P. Car A is traveling at VÅ = 129 km/h as it passes P, but over the next 4.9 seconds, the car uniformly accelerates to 149 km/h, after which that speed is maintained. At the moment when A passes P, the police car begins to accelerate at the constant rate of 4.4 m/s² until a speed of 177 km/h is achieved, and that speed is then maintained. Determine the distances required for the police officer to overtake car A. A Answer: s= VA P m

A car stops 4 seconds after the application of the brakes while covering a rectilinear stretch 337 feet long. If the motion occurred with a constant acceleration a, determine the initial speed of the car and the acceleration a. Express v in mile-per-hour (mph) and a in terms of g, the acceleration of gravity. S