I believe it is ionic try it
The earth has less creators because there is a protective atmosphere which makes the asteroids burn up before they hit the surface of earth. Which means by the moon not having an atmosphere small rocks are easily colliding with the moons surface.
Answer:
a)Total distance = 399. 5 m
b)Total time =51.51 sec
c)Average speed = 7.75 m/s
Explanation:
For A to B:


v= u + at
8.33 = 0.42 x t
t=19.83 sec
1 Km/h=0.27 m/s
30 Km/h=8.33 m/s

s=82.6 m
For B to C
V= 8.33 m/s
s= V x t
s=8.33 x 30
s=249.9 m
For C to D

v= u - at
Final speed v=0
So
s=v x t/2
7= 8.33 x t/2
t=1.68 sec
Total distance = 82.6 + 249 .9 +7
Total distance = 399. 5 m
Total time = 19.83 + 30 + 1.68
Total time =51.51 sec
Average speed =Total distance/Total time
Average speed = 399.5/51.5
Average speed = 7.75 m/s