14. In towns and cities, the speed limit is 60 km-hr-1. The length of the average car is 3.5 and the width of the average car is 2 m. In order to cross the road, you need to be able to walk further than the width of a car, before that car reaches you. To cross safely, you should be able to walk at least 2 m further than the width of the car (4 m in total), before the car reaches you. (a) If your walking speed is 4 km-hr- ", what is your walking speed in m-s-1? (b) How long does it take you to walk a distance equal to the width of the average car? (c) What is the speed in m-s-1 of a car travelling at the speed limit in a town? (d) How many metres does a car travelling at the speed limit travel, in the same time that it takes you to walk a distance equal to the width of car? (e) Why is the answer to the previous question important? (f) If you see a car driving toward you, and it is 28 m away (the same as the length of 8 cars), is it safe to walk across the road; (8) How far away must a car be, before you think it might be safe to cross? How many car-lengths is this distance? 15. A bus on a straight road starts from rest at a bus stop and accelerates at 2 m-5-2 until it reaches a speed of 20 m-5-1. Then the bus travels for 20 s at a constant speed until the driver sees the next bus stop in the distance. The driver applies the brakes, stopping the bus in a unitorm manner in 5 5 (a) How long does the bus take to travel from the first bus stop to the second bus stop? (b) What is the average velocity of the bus during the trip