Question

554 km – 3 sig figs
1.01 x 10^5 m – unlimited
0.00099 s – 2 sig figs
4500 km – 2 sig figs
7 pennies – 1 sig fig
21,000 m – 2 sig figs

Answer 1

@Vocaloid

Answer 2

good except for 1.01 * 10^5, we consider the front part of the number (1.01) when considering sig figs

Answer 3

since it just ends up being 101000, the last three zeros are insignificant

Answer 4

554 km – 3 sig figs
1.01 x 10^5 m – 3 sig figs
0.00099 s – 2 sig figs
***1.4500 km – 3 sig figs***
7 pennies – 1 sig fig
21,000 m – 2 sig figs

Answer 5

ok I know this is kind of confusing but trailing zeros after a decimal point are significant

so 1.4500 actually has five sig figs

Answer 6

okay so for 1.4500 its 5 and everything else is okat

Answer 7

in 1.01 x 10^5, does the 10^5 not count like just look at the first number?

Answer 8

well, multiplying a number by 10 just adds extra 0's on the end so any multiple of 10^n won't add any significant digits

Answer 9

554 km – 3 sig figs
1.01 x 10^5 m – 3 sig figs
0.00099 s – 2 sig figs
***1.4500 km – 5sig figs***
7 pennies – 1 sig fig
21,000 m – 2 sig figs

Answer 10

yup good

Answer 11

Got it thanks!

Answer 12

its saying this : You sorted 1 out of 6 items incorrectly. 7 pennies refers to a discrete number of objects and is considered an exact number.

Answer 13

oh whoops >> I forgot about that rule

yeah, if you have a known discrete unit it's infinite sig figs. for example 12 items = a dozen would have infinite sig figs