Question

carry out the following operations as if they were calculations of experimental results, and express each answer in the correct units with the correct number of significant figures

(7.8 m minus 0.34m)(1.5 s +0.82 s)

Answer 1

(7.8 m - 0.34m) (1.5 s +0.82 s)

(7.8 m - 0.34m) = 7.46

                          = 7.5   (after decimal point only one sigfig)

(1.5 s +0.82 s)   = 2.32

                           = 2.3 (after decimal point only one sigfig)

now : 7.5 x 2.3 = 17.25

                             = 17 (only 2 sigfigs)

answer :   17.