Answer:
0.00125 km.
Explanation:
Given,
- Speed of the horse on which princess travelling, v = 9km/h
- Time taken by Lysera to sneeze = 0.5 s
As we know
1 hour = 3600 seconds



So, time taken by Lysera to sneeze can be given by,

According to definition of speed,

=>distance = speed x time

= 0.00125 km
Hence, Princess Gray down will moved by 0.00125 km.