Chapter 2, Problem 89A

Interpretation Introduction

Interpretation:

The given figure below needs to be observed and the measurements to the correct number of significant figures needs to be recorded.

Concept introduction:

In order to determine the number of significant figures, the following rules should be applied,

1. The non-zero digits are always significant.

2. In a number, the zeros to the left of the first non-zero digit are not significant.

3. Zeros between non zero digits are significant

4. Zeros to the right of the decimal place are significant

5. If a number ends in zero that are not to the right of a decimal, the zeros may or may not be significant.

To round off a number, look at the digit up to which number needs to be rounded off. If the digit right to it is less than 5 simply add 1 to the previous digit and remove all the digits after it from the number. If the digit right to the digit up to which rounding needs to be done is less than 5, just remove all the digits after it from the number.

Now, if the digit is equal to 5 then 1 is added to the previous digit if it is an odd number. If the previous digit is an even number, simply remove all the digits after it from the number.

Answer to Problem 89A

The correct measurement of the clip will be $5.85$ centimeters.

Explanation of Solution

To record the measurements to the correct number of significant figures, determine which digit needs to be estimated. Form the figure, the paper clip crosses the $5.8$ line. The last digit must be estimated. There are 10 divisions in 1 cm as shown in the figure. Since he line crosses the 8^th division i.e. in the middle of 8^th and 9^th division indicating 0.85 cm. Therefore, the correct measurement of the clip will be $5.85$ centimeters (cm) with the last digit being estimated.

Conclusion

The correct measurement of the clip will be $5.85$ centimeters.