Final answer:
A busway passing vertically through a floor must be totally enclosed up to 300 units above the floor. The margin of error in this act is equal to the height of the bus, which is 20.0 m.
Step-by-step explanation:
In order to pass vertically through a floor, a busway must be totally enclosed up to a certain height above the floor. The answer options provided are -1000, -600, -300, and -450.
The correct answer is -300. This means that the busway must be enclosed up to 300 units above the floor.
If the top of the takeoff ramp is at the same height as the bus tops and the buses are 20.0 m long, the margin of error in this act can be calculated. The range is the horizontal distance the bus must travel to miss the end of the last bus. The range is greater than the horizontal distance by the height of the bus, in this case, 20.0 m.