Chapter 1, Problem 32P

A civil engineer needs to establish the elevation of the cornerstone for a building located between Iwo benchmarks, B1 and B2, of known elevations, as shown in

The elevation E along the grade satisfies the linear relationship

$E=ml+E_1$ (1.20) where El is the elevation of B 1, l is the taped distance from B1 along the grade, and in is the rate of change of E with respect to l.

(a) Find the equation of the line E and determine the slope of the linear relationship.

(b) Using the equation of the line from part (a), find the elevation of the cornerstone E* if it is located at a distance $l=300$ in from B1.

(c) Sketch the graph of £ as a function of l and clearly indicate both the slope in and elevation $E_1$ of 81.