The speed s in miles per hour that a car is traveling when it goes into a skid can be estimated by using the formula s = sqrt 30fd, where f is the coefficient pf friction and d is the length of the skid marks in feet. After an accident, a driver claims to have been traveling the speed limit of 45 mi/h. The coefficient of friction under accident conditions was 0.7. Is the driver telling the truth about his speed?
To answer this question, we need to calculate the length of the skid marks in feet. Using the formula, we can calculate that the length of the skid marks should be approximately 33.3 feet. If the length of the skid marks is 33.3 feet, then the speed of the car is indeed 45 mi/h, which means the driver is telling the truth about his speed.
