Answer: 1010.92 m/s
Explanation:
According to Newton's law of universal gravitation:
(1)
Where:
is the gravitational force between Earth and Moon
is the Gravitational Constant
is the mass of the Earth
is the mass of the Moon
is the distance between the Earth and Moon
Asuming the orbit of the Moon around the Earth is a circular orbit, the Earth exerts a centripetal force on the moon, which is equal to :
(2)
Where 
is the centripetal acceleration given by:
(3)
Being 
the orbital velocity of the moon
Making (1)=(2):
(4)
Simplifying:
(5)
Making (5)=(3):
(6)
Finding :
(7)
(8)
Finally:
Find the average speed and the average velocity.
Average speed = distance / time
distance = 10 x 8000 m = 80,000 m
time = 20 min * 60 s/min = 1200 s
Average speed = 80,000 m / 1200 s = 66.67 m/s
Average velocity = displacement / time
Given that the race car made complete circles the final poin is the same initial point, then its displacement is zero and the average velocity is zero too.
B.) The moon
There you go.
