When multiplying or dividing measured quantities, what determines the number of significant figures in the result?

Solution 27 E: The temperature scale can be kelvin (K), centigrade ( C) and Fahrenheit ( F). o K= C + 273.13 , C= 5/9( F-32) or F=9/5( C)+32 o (a) 72 °F to °C Conversion of temperature from °F to °C We know, oC= 5/9( F-32) =5/9(72-32) = 5/9 x 40 =22.22 C o Thus the temperature in Celsius is 22.22 C (b) 216.7 °C to °F, Conversion of temperature from °C to °F We know, o C= 5/9( F-32) or F=9/5( C)+32 = 9/5(216.7)+32 = (390.06+32) °F = 422.06 °F Thus the temperature in Fahrenheit ( F). is 422.06 °F c) 233 °C to K Conversion of temperature from °C to K We know K= C + 273.13 = (233 +273.13) K = 506.13 K Thus the temperature in Kelvin is 506 K (d) 315 K to °F, Here two unit conversion is required Conversion K to °C We know K= C + 273.13 o C = K-273.13 = 315-273.13 = 41.85 Co o Conversion of 39.87 C to °F oC= 5/9( F-32) o o or F=9/5( C)+32 = 9 x 41.85 +32 5 = 75.33 +32 o = 107.33 F o o Thus the temperature in Fahrenheit ( F). is 107.33 F (e) 2500 °F to K Here two unit conversion is required Conversion °F to K We know Conversion of 2500 C to °F o o o C= 5/9( F-32) =5/9(2500-32) = 5/9(2468) = 1371.1 C o o Conversion of C to K o K= C + 273.13 = 1371.1+273.13 = 1644.2 K Thus the temperature in Kelvin (K). is 1644.2 K (f) 0 K to °F. Here two unit conversion is required Conversion K to °C We know o K= C + 273.13 C = K-273.13 = 0-273.13 o = -273.13 C Conversion of -273.13 C to °F o oC= 5/9( F-32) or F=9/5( C)+32 = 9/5 (-273.13)+32 = -491.63 +32 = -459.63 F o o Thus the temperature in Fahrenheit ( F). is -459.63 F