4. a high school athlete runs 400 m in 52.20 sec. what is his speed in mph?
14100
1110

28,800m/p second

Explanation:

Calculate the distance per second so, 400m/50 s= 8m/p second now knowing the speed/hour and knowing an hour has 3,600 seconds,multiply it by 8 then you will get 28,800m/p second, or 28.8km/h

c because the action was the roller coaster reaches bottom of hill (action) reaction would be blood tends to drain away from head

hope this !