2. (4 pt) The diameter of human hair is about 50 um. (a) What is this in inches? (b) How many hair widths is 20.0 cm, the typical size of human head? 3. (6 pt) Determine the conversion factor between (a) m/s and mi/h, (b) km/hr and m/s, and (c) mi/hr and in/s. 4. (3 pt) How much longer (percentage) is a 5 k race than a 3 mile race? 5. (2 pt) Superman flies by you at 100 mi/hr just when Batman runs by you at 4 mi/hr. Does Superman necessarily have a greater acceleration? Explain. 6. (3 pt) You travel for 10 mi at a constant speed of 30 mi/h. Then you travel another 10 mi at 50 mi/hr. What is the average speed of the entire trip