13. Average speed is calculated by: a. Time divided by distance b. Distance divided by time c. Distance multiplied by time d. Time squared divided by distance 14. In scientific notation, 0.00302 is written as: a 3.02times 10^wedge -2 b 3.02times 10^wedge -3 C 3.02times 10^wedge -4 d 3.02times 10^wedge -5 15. Which SI base unit represents amount of substance? a. Mole b. Gram c. Kilogram d Candela

13. The correct answer is b. Distance divided by time. Average speed is calculated by dividing the total distance traveled by the total time taken.<br /><br />14. The correct answer is b. $3.02\times 10^{\wedge }\{ -3\} $. In scientific notation, 0.00302 can be written as $3.02\times 10^{\wedge }\{ -3\} $.<br /><br />15. The correct answer is a. Mole. The SI base unit that represents the amount of substance is the mole.