Significant figures refers to digits within a number which must be included in other depict correct quantity of the figure.
- 4.29478416 = 4.2947842 ( 8 significant figures)
- 4.29478416 = 4.29478 (6 significant figures)
- 4.29478416 = 4.295 ( 4 significant figures)
- 4.29478416 = 4.3 (2 significant figures)
To round a number to a certain number of significant figures,
- Only leading 0 which comes before the decimal Point are regarded as insignificant.
- Once the number of significant figures have been identified, the next number after this is either rounded up to 1 and added to the last value(if number is ≥5) or rounded to 0 (if number is less than 5)
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now, a line perpendicular to that one, will have a "negative reciprocal" slope, thus
Answer:
2.9 years
Step-by-step explanation:
Given that :
Half-life t1/2 = 9 years
Initial mass = I = 70 grams
A = final mass = 56 grams
t = time taken to reach final amount
Using the exponential half life relation :
A = I(0.5)^t/t1/2
56 = 70(0.5)^t/9
56/70 = 0.5^t/9
0.8 = 0.5^t/9
Log 0.8 = log 0.5^t/9
−0.096910 = −0.301029 * t/9
t/9 = 0.096910 / 0.301029
t/9 = 0.3219291
t = 0.3219291 * 9
t = 2.8973619
t = 2.9 years
Answer:
c. 15
Step-by-step explanation: 15 is divisible by 3