7. (10 points) A and B are running a 10 km race. A completes the race in 50 minutes, at which point B is still 500 meters from the finish line. To give B a chance, they agree that in the second race, A will start 500 meters behind the starting line. Assuming both run at the same speed in both races, when the first person reaches the finish line in the second race, the other person will be $\qquad$ meters from the finish line.
【Analysis】First, find the invariant, which is time. The time for the two people to run twice is the same, and the distances are in a proportional relationship.
【Solution】Solution: According to the problem, we know:
When Jia runs the full 10 kilometers, which is 10000 meters, Yi runs $10000-500=9500$ meters, and the time taken by both is the same, with the distances in a proportional relationship.

That is, 10000: $9500=20: 19=(10000+500): 9975$.
When Jia runs 10500 meters, Yi runs 9975 meters.
He is still short of $10000-9975=25$ (meters).
Therefore, the answer is: 25