Building a better rollercoaster
Suppose you are asked to design the first ascent and drop for a new roller coaster. By study-ing photographs of your favorite coasters, you decide to make the slope of the ascent 0.8 and the slope
of the drop —1.6. You decide to connect these two straight stretches y = Li(z) and y = L2(x) with part of a parabola y = f(x) = ax'- + bx + r, where x and f(x) are measured in feet. For the track
to be smooth there can't he abrupt changes in direction, so you want the linear segments Li and 1., to be tangent to the parabola at the transition points P and Q. (See the figure..) To simplify
the equations, you decide to place the origin at P. 1. (a) Suppose the horizontal distance between P and Q is I00 ft. Write equations in (Lb, and c that will ensure that the crack is smooth at the
transition points. (b) Solve the equations in pan (a) for a, iv, and c to find a formula for f(x). (c) Plot LI, f, and Lt to verify graphically that the [rang' tions are smooth. (d) Find the
difference in elevation between P and Q.