Answer: East Coast
Step-by-step explanation:
The problem states we need to find whether the person is on the East Coast or West Coast.
Now, we know that the shadow is shortest when the Sun is at the highest point in the sky. So it means the noon time is 12:00 P.M. Now this is the local noon time which you have set in Kansas City. Now you flew to the Coast and it says 10:00 am which means you have traveled to a place where noon comes early. And noon comes early on Eastern Coast so you are on the East Coast.