We first need to convert the 54 mph to feet per second. So converting this will give us the value of 79.2 ft per second.
Solution:
v = at
d = 1/2 at^2
79.2 = 29t
Dividing both sides by 29, will gives us the result of 2.73.
meaning it takes 2.73 seconds to stop)
d = 1/2 (29) 2.73^2 = 29.81 feet to stop.