That would be the Earth's rotation. Hope this helps!
Bella’s average velocity is about 0.693 meters per second.
To find the average velocity, you must divide the distance by the change in time, which should look like v=d/t
Here is how you set up the equation-
v=6.1/8.8
Once you divide 6.1 meters by 8.8 seconds, you should get a number that looks like 0.69318182.... however, I just rounded it to 0.693 meters per second. You can round it to whatever you like.
Hope this helped! If you have any questions about what I mentioned in my answer or explanation, feel free to comment on my answer and I’ll try to get back to you!