1 more physics question...PLEASEEEEEEEEEE help!!!!!!!!?

Question

A driver traveling at 58 km/h sees a chicken dash out onto the road and slams on the brakes. Accelerating at -7 m/s2, the car stops just in time 23.8 m down the road. What was the driver's reaction time (i.e., the time that elapsed before he engaged the brake)?

If u don't know for sure, please don't try. Thanks!

YAYY 0.33, and I got it right!!! Thanks sooooo much...the first person, I couldn't really understand what you were saying with traction and all, so I couldn't follow your instructions, but the second answer got me to it. Thanks!! I am giving the first two thumb upz and the second best answer. Thanks sooooooooooo much!!!!!!!!!

Also, please help me out with my other physics questions!!! Thanks!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 1

v = sqrt(2ad); so that v^2/2a = d; where v = 58 kph and a = 7 m/sec^2. Change the v units to mps for consistency and solve for d, which is the stopping distance when decelerating from v = 58 kph down to v = 0, with a deceleration a.

Then D = d + vt; where D = 23.8 m, the total stopping distance, which consists of the deceleration distance plus the distance traveled at v = 58 kph for t seconds, which is the reaction time. Thus (D - d)/v = t, again ensuring v is in mps.

You can do the math.

Answer 2

here is a better question:
who had the fastest reaction time ever measured??
(this would have been in the 1960s)

hint 1= he made his " living" with his reaction time


hint 2 = an athlete not a racecar driver


hint 3= still one of the most famous athletes in the world






answer (written backwards) = ila dammahum

Answer 3

initial velocity = vo=58 km/h = 16.1 m/s
a= -7 m/s2, vf = final velocity =0
vf =vo+ at
t= vo/a
t=2.3 s
s=0.5at^2 +vo*t
s(2.3)=18.515 m
s1 = 23.8 - 18.515
s1=9.785 m
tr= s1/vo
tr= 0.608 s
tr is the reaction time