Physics  correction  significant digits
posted by Anonymous .
1) How many SD's?
a) 5.7 = 2 SD
b) 235.12 = 5 SD
c) 8.07 = 3 SD
d) 0.0032 = 2 SD
e) 0.0150 = 3 SD
f) 1.39x10^5 = 3 SD
g) 15.200 = 5SD
h) 1070 = 3 SD
2) Calculations  Please check the SDs
a) 15.3 + 25.03
= 40.33
= 40.3
b) 1200 + 63
= 1263
= 1300
c) 4.78  1.2
= 3.58
= 3.6
d) 243.1 + 15.2 + 3.75
= 262.05
= 262.1
e) 0.00170 + 0.02561
= 0.02731
= 0.0273
f) 4.0  3.99
= 0.01....
g) 2.7x82.7
= 223.29
= 220
h) 1074x3.21
= 3447.54
= 345
i) 0.022 x 9.7
= 0.2134
= 0.21
j) 0.0220 x 9.70
= 0.2134
= 0.213
k) 23.5/2.0
= 11.75
= 10
l) 0.1735/23
= 0.00754
= 0.0075
m) 18.2 x 27.9 x 1.3
= 660.114
= 660
n) 6.7x2.73/14.74
= 1.240
= 1.24
3) What units would result?
a) cm/s x s
= cm
b) m^2/s
=
c) m/s^2 x s
= m/s
d) m/s / s
=
e)g/cm^3
=
f) kg/m^2 / m
=

2 e,f n are wrong
3. the answers shown are correct, but several are blank. 
The reason (e) is incorrect is that, even though 0.00170 has three sig. digits, this is an addition problem, so only five places to the right of the decimal are required to match the significance of the 0.02561

no because i would not quit