Question

a balance determines the mass of object a to be 45.1 kg. a different balance determines the mass of object b to be 33.46 kg. if you were to add these two masses and round the result to the correct number of significant figures, what would their total mass be?

Explanation:

Step1: Add the two masses

$45.1+33.46 = 78.56$

Step2: Determine significant - figures for addition

When adding, we look at the decimal - place of the least precise measurement. 45.1 has one decimal place and 33.46 has two decimal places. We round the result to one decimal place.

Step3: Round the result

Rounding 78.56 to one decimal place gives 78.6

Answer:

78.6 kg