Final answer:
The numbers 18.34 cm, 9.02603 cm, 20.2 cm, and 150 cm have four, six, three, and two significant figures respectively. Additional examples are given to help in understanding how to count significant figures in different types of numbers.
Step-by-step explanation:
When determining the number of significant figures in a measurement, you count all the digits that are known accurately, plus one last digit that is somewhat uncertain or estimated. Here's how to determine the significant figures for each of the given measurements:
- A) 18.34 cm has four significant figures.
- B) 9.02603 cm has six significant figures.
- C) 20.2 cm has three significant figures.
- D) 150 cm has two significant figures; if it was written as 150.00 cm, it would have five significant figures as the trailing zeros after a decimal point are significant.
Let's look at additional examples:
- a. 0.0009 has one significant figure (leading zeros are not significant).
- b. 15,450.0 has six significant figures (trailing zeros after a decimal point are significant).
- c. 6x10³ has one significant figure (in scientific notation, only the digits before the multiplication sign count).
- d. 87.990 has five significant figures (including the trailing zero after the decimal).
- e. 30.42 has four significant figures.
Remember that the number of significant figures plays a critical role in the accuracy and precision of measurements and calculations.