![A parabolic vertical curve is being designed to join a road of grade +5% with a road of grade -3%. The length of the vertical curve is 400 m measured along the horizontal](https://www.gkseries.com/blog/wp-content/uploads/2023/07/A-parabolic-vertical-curve-is-being-designed-to-join-a-road-of-grade-5-with-a-road-of-grade-3.-The-length-of-the-vertical-curve-is-400-m-measured-along-the-horizontal.jpg)
Q. A parabolic vertical curve is being designed to join a road of grade +5% with a road of grade -3%. The length of the vertical curve is 400 m measured along the horizontal. The vertical point of curvature (VPC) is located on the road of grade +5%. The difference in height between VPC and vertical point of intersection (VPI) (in m, round off to the nearest integer) is
Solution:
n1=0.05
n2=−0.03
L=400 m
The difference in the height between VPC and VPI,
y=n1×L/2
=0.05×400/2
=10 m
![](https://www.gkseries.com/blog/wp-content/uploads/2023/07/image-202.png)