To solve this problem, we need to first convert the distance on the map to actual distance using the map scale.
1 cm on the map represents 50,000 cm (or 500m) in actual distance.
So, 8.5 cm on the map represents 8.5 x 500m = 4,250m in actual distance.
Now, we can use the formula: time = distance ÷ speed
Here, distance = 4,250m and speed = 10km/h = 10,000m/h
So, time = 4,250m ÷ 10,000m/h = 0.425 hours
To convert hours to minutes, we can multiply by 60:
time = 0.425 x 60 = 25.5 minutes
Therefore, it will take Myra 25.5 minutes to run from the park entrance to the beach.