Organic acids are of two types. One has the COOH group (the carboxyl group). An example is acetic acid (CH3COOH), the acid in vinegar. It is made by oxidizing grain alcohol or by the fermentation of the fruit sugar in cider. The other type has a phenol group, as in phenol (C6H5OH).
Calculate the total braking distance. This formula is 1/2 the initial velocity in feet per second multiplied by the time required to stop, which is 0.5 x 102.7 x 5.135 = 263.68. The calculated thinking distance is 2 x 102.7 = 205.4. Add the two numbers together. 469.08 feet is the total braking distance.
From our answers in part (a), we see that the speed for a braking distance of 500 ft is between 60 mph and 90 mph. Estimates within this range can vary, though based on the computations, it is reasonable to predict a velocity closer to 90 than to 60. The figure shows a graph of $d = 2.2v + v^2/20$. We see that the speed corresponding to a braking distance of 500 ft is approximately 80 mph.