Haley is driving down a straight highway at 73 mph. a construction sign warns that the speed limit will drop to 55 mph in 0.50 mi.
what constant acceleration (in m/s2) will bring haley to this lower speed in the distance available?

Explanation:

We know Haley is driving with an initial velocity of and then she has to change to a velocity of in a distance , and we also know we are dealing with constant acceleration  .

Therefore, the following equation will be useful:

(1)

Clearing :

(2)

(3)

(4)

Knowing and :

this is the constant acceleration that will bring Haley to lower speed