Practice Question: Find the Middle Ordinate on a Horizontal Curve

Answer: A) 13 ft

Refer to PE Civil Reference Handbook V 1.1 Section 5.2.1 basic curve elements:
\(M=R-R\cos\frac∆2\)
where:
\(\Delta=Intersection\ Angle\)
\(R=1500\ ft\)
\(T=R\tan\frac∆2\)
\(197=1500\tan\frac∆2→ ∆ =15\ degrees\)
\(M=1500-1500\cos{\left(\frac{15}{2}\right)}=12.8\ ft\)