Question

A driver on a leveltwo-lane highway observes a

Answer 1

Answer:

SSD = 565.54 ft

Explanation:

Given data:

driver speed = 60 mph

clear distance available to stop the truck on emergency can be calculated by using stopping sight distance

SSD = Lag distance  +  breaking distance

$SSD = vt + \frac{v^2}{2gf}$

let take comfortable acceleration rate as a =  11.2 ft/s^2

g =32.2 ft/s^2

a = fg

$f = \frac{11.2}{32.2} = 0.348$

speed is given as 60 mph

we know that 1 mile 5290 ft

i hr = 3600 sec

therefore v = 88 ft./s

from standard assumption time to reaction is taken as 2.5 sec

so $SSD = 88 \times 2.5 + \frac{88^2}{2\times 32.3\times 0.348}$

SSD = 565.54 ft