# Physics - correction - significant digits

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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
=

• Physics - correction - significant digits -

2 e,f n are wrong
3. the answers shown are correct, but several are blank.

• Physics - correction - significant digits -

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

• football -

no because i would not quit