Find the average acceleration of a northbound subway train that takes 0.90 seconds to go from 12 m/s to 4.5 m/s.

a= -8.33

Step-by-step explanation:

it will be deceleration because he was 12 m/s then go to 4.5 m/s

and by applying moving equation

=+at

we have all but not have a  

36/60

36/2=18

60/2=30

18/30

18/3=6

30/3=10

6/10

6/2=3

10/2=5

your final answer would be 3/5 of an

hope this !