3. A temporary sign has set up on a freeway due to a downstream accident. The letter high of the sign is 4 inches. Assume that a driver can read a road sign at a distance of 40 ft for each inch of letter height. The speed limit of the freeway is 70 mph, but 30 mph is advised at the crash site. a. How far back can the sign be read? b. How much distance will have been traveled before drivers are able to apply brake?