Class Example

Drivers with an average of $20/40$ vision travel on a freeway. The total distance covered during perception reaction time and braking to the exit is $450ft.$ Assume that the sign placed ahead of the exist is $6-$in letters and the drivers with $\frac{20}{20}$ vision can read the sign at $60ft$ per inch of letter height.

a$)$ Determine the distance a $\frac{20}{20}$ driver can read a $6-$inch sign

b$)$ Determine the distance a $\frac{20}{40}$ driver can read a $6-$inch sign

c$)$ What should be the minimum distance of sign with $6-$in letters placed ahead of the exit?