Answer:
Explanation:
Use the one-dimensional equation
[tex]v_f=v_0+at[/tex] which says that the final velocity of an object is equal to the object's initial velocity plus its acceleration times time. We are looking for time. That means the equation looks like this:
0 = 30 + (-4)t and
-30 = -4t so
t = 7.5 sec
