11
I've already done this in another question answered just before this one. Just follow what I did with that question.
12.
Givens
Every driver should know the answer to this question. It is an amazing difference.
vf = 0
vi = 59 m/h
d = ???
a = a constant
v1a = 25 m/h
Formula
vf^2 = vi^2 + 2* a*d
vf = 0 and a is negative. Also you don't have to make any conversions since you seek a ratio
- vi^2 = 2*-a * d
(59 m/s^2/ (25 m/s)^2 = (2 -a * d1) / (2 - a * d)
(59/25)^2 = (d / d1)
5.56 = d1/d2
The answer is C.
13
You should be able to do this on your own. The only trick is to convert the km to meters.
d = 3.7 km = 3.7 km * 1000 m/km = 3700 m
vi = 0
vf = 26 m/s
a = ??
formula
vf^2 = vi^2 + 2* a* d
26^2 = 0 + 2*2700 * a
576 =5400*a
576 / 5400 = a
a = 0.125 which they have rounded to 0.12
Answer E.
