The “reaction time” of the average automobile driver is about 0.7 s. (the reaction time is the interval between the perception of a signal to stop and the application of the brakes.) if an automobile can slow down with an acceleration of 12 ft/s squared 2 compute the total distance (in feet) covered in coming to a stop after a signal is observed from an initial velocity of 55 mi/h. let 1 mi/h = 1.466 ft/s.

Remark

Every driver should know this especially if you live in cold country (like Minnesota).

Calculation Reaction time distance

t = 0.7 second

r = 55 mph (you need to convert this) to feet per second.

1 mph = 1.466 ft/s

55 mph = x Cross multiply

x = 55 mph * 1.466 feet /sec

x = 80.63 feet/second

d = ???

d = 80.63 ft/s * 0.7 sec

d = 56.44 ft. Distance to stop for the reaction time.

That is your reaction distance. Your initial speed is 80.63 feet / second

Givens: deceleration

vi = 80.63 ft/s

vf = 0 ft/s

a = -12 ft/s^2

d = ?

Equation

vf^2 = vi^2 + 2*a*d

Solve

0 = 80.63^2 + 2(-12) * d

- 6501 = -24 d

d = 271 feet to decelerate to zero

The total distance needed to stop is 271 + 56.44 = 327

Answer B

1

x = 1

step-by-step explanation:

0 ÷ x = 0

0 ÷ 1 = 0