Final answer:
The equation representing the path of a roller coaster with its vertex at the origin and focus 25 feet above it is y = x^2/100. The vertical height at a track width of 20 feet is 1 foot. When the roller coaster is at a height of 25 feet, the track width is 50 feet.
Step-by-step explanation:
To represent the path of the roller coaster with the vertex at (0,0) and the focus 25 feet above it, we use the standard form of a parabolic equation: y = ax^2. Since the focus is 25 feet above the vertex, we can determine 'a' using the equation 1/(4a) = 25, which gives us a = 1/100. Thus, the equation representing the path is y = x^2/100.
For a parabolic track with a width of 20 feet, the equation tells us that this width occurs at a certain height 'h'. Setting this distance as the 'x' value and solving for 'y', we find that y = (10)^2/100 = 1 foot. Therefore, the vertical height of the roller coaster in relation to the vertex when the width is 20 feet is 1 foot.
Conversely, to find the width when the roller coaster is at a height of 25 feet, we set 'y' to 25 in the equation and solve for 'x' to get x = ±sqrt(2500), which results in a width of 50 feet (the distance from 'x' to '-x').