(II) A sports car accelerates approximately as shown in the velocity-time graph of Fig. 2–43. (The short flat spots in the curve represent manual shifting of the gears.) Estimate the car's average acceleration in (a) second gear and (b) fourth gear. 50 5th gear 4th gear 40 3rd gear 30 20 2nd gear 10 1st gear t (s) 0. 10 20 30 40 FIGURE 2–43 Problem 56. The velocity of a car as a function of time, starting from a dead stop. The flat spots in the curve represent gear shifts. (s/u)a

The driver of a car slams on the brakes when he sees a tree blocking the road. The car slows uniformly with an acceleration of 5.60 m/s2 for 4.20 s, making straight skid marks 62.4 m long, all the way to the tree. With what speed does the car then strike the tree?

2) A police officer is in pursuit of a riding in tandem who was suspected to have snatched a cellphone along a busy road. If the motorcycle used by the officer to catch the culprits is traveling at 20 m/s to 40 m/s just in time to catch the culprits, what is the distance covered by the police officer if it took him 10 seconds to do so?

(II) A driver is traveling 18.0 m/s when she sees a red light ahead. Her car is capable of decelerating at a rate of 3.65 m/s2 If it takes her 0.350 s to get the brakes on and she is 20.0 m from the intersection when she sees the light,will she be able to stop in time? How far from the beginning of the intersection will she be, and in what direction?

(c) Tests reveal that a normal driver takes 0.75 s before he or she can react to a situation to avoid accident or collision. It takes about 3.00 s for a driver with having 0:10% of alcohol in his syst em to do the same. If such drivers are travelling on a straight road at 44:00 ft=s and their cars decelerates at 0:68 m-s, ded ermine the shortest st opping distance, d, for each from the moment they see the pedestrians. Refer to Figure 1. [1 m = 3.2808399 ft] 2

33. (II) A 75-m-long train begins uniform acceleration from rest. The front of the train has a speed of 18 m/s when it passes a railway worker who is standing 180 m from where the front of the train started. What will be the speed of the last car as it passes the worker? (See Fig. 2–38.) -75 m- v = 18 m/s FIGURE 2–38 Problem 33.

' A car and train move together along parallel paths at 25.0 m/s, with the car adjacent to the rear of the train. Then, because of a red light, the car undergoes a uni- form acceleration of - 2.50 m/s² and comes to rest. It remains at rest for 45.0 s and then accelerates back to a speed of 25.0 m/s at a rate of 2.50 m/s². How far be- hind the rear of the train is the car when it reaches the speed of 25.0 m/s, assuming that the speed of the train has remained 25.0 m/s?

(II) Roger sees water balloons fall past his window. He notices that each balloon strikes the sidewalk 0.83 s after passing his window. Roger’s room is on the third floor, 15 m above the sidewalk. (a) How fast are the balloons traveling when they pass Roger’s window? (b) Assuming the  balloons are being released from rest, from what floor are they being released? Each floor of the dorm is 5.0 m high.

(II) A space vehicle accelerates uniformly from 85m/s  at t=0 to 162 m/s at 10.0 s How far did it move between t=2.0s and t=6.0 s