-The brakes on your automobile are capable of creating acceleration of 19 ft/s2. If you are going 76 mi/hr and suddenly see a state trooper, what is the minimum time required to get your car to 55 mi/hr?

For this answer, I got 1.62 s.

-How far do you travel while returning to the legal speed limit?

I have no idea how to get this answer.
Which equation can I use?

5 answers

the formula that helps is: distance = v * t + (1/2)(a *t^2). Where a=acceleration, v=initial velocity, and t=time. Be very mindful of the sign for acceleration.
v is 76 mi/hr, right?
**Oops sorry, my sister was using this site last night for Chemistry.
76mi/hr= 111 ft/sec
55mi/hr=80.7ft/sec

Vf=Vi + at
80.7=111 - 19*t
t= 1.60 sec check that

avg velocity= (111+80.7)/2= 96.1ft/s

distance= avg velocity *time
Ok great, I get it now. Thanks!