Question

1. Some wooden rulers do not start with 0 at the edge, but have it set on a few millimeters. How could this improve the accuracy of the ruler?
2. You find a micrometer that has been badly bent. How would it compare to a new, high-quality meter stick in terms of precision? Its accuracy?
3. Does parallax affect the precision of a measurement that you make? Explain.
4. A box has a length of 18.1 cm and a width of 19.2 cm and it is 20.3 cm tall.
a. what is the volume?
b. how precise is the measure of length? Of volume?
c. How tall is a stack of 12 of these boxes?
d. how precise is the measure of the height of one box? Of 12 boxes?

Answer 1

1. Some wooden rulers do not start with 0 at the edge, but have it set on a few millimeters because the cut of the woof alters the length of the first measures. Moreover, some objects are difficult to be aligned on the ruler, thus, in order to remove this difficulty, some wooden rulers do not start with 0 at the edge.

2. The micrometer has been badly bent which means that it will not measure properly and will not be perfectly parallel with the surface to be measured. This distortion will  change its precision. The device should be parallel with the surface to be measured in order to maintain its accuracy.

3. No, the parallax will not affect the precision of a measurement that we take as precision  is the closeness of the readings and the readings are already precise, thus taking the reading with the same parallax won't impair the precision but decreases the accuracy.

4. Length of box=18.1 cm, width= 19.2 cm and height=20.3 cm, then the a.volume=length×width×height

=$18.1{\times}19.2{\times}20.3$

=$7050cm^{3}$

b. The reading of the length is precise to 0.1 centimeters, while the volume's reading is precise to 10 cm³.

c. The stack of 12 of the boxes has height=$12{\times}19.3$

=$232cm$

d.The measure of one box is precise to 0.1 cm, while the measurement of the combined boxes is precise to 1 cm.

Answer 2

1. The end of a ruler is prone to become worn and it is also difficult to align the object being measured to the end at times. By beginning the markings of the ruler with a offset, we prevent these problems and increase the accuracy of the readings.

2. The readings may still be precise as the micrometer is a precise instrument; however, the bending will definitely impair its accuracy because the readings will not be equivalent to the actual value.

3. No, it does not. Precision is the closeness of readings to one another, and readings are precise when they have minimal variation. Taking readings with the same parallax error will not impair the precision, but it will definitely decrease accuracy

4.

a.
Volume = length * width * height
V = 18.1 * 19.2 * 20.3
Volume = 7050 cm³

b.
The reading of the length is precise to 0.1 centimeters, while the volume's reading is precise to 10 cm³ as it is stated in three significant figures

c.
The box will be stacked with the big base on the bottom, so the height of the stack will be the combined widths of the boxes.
Height = 12 * 19.3
Height = 232 cm

d.
The measure of one box is precise to 0.1 cm, while the measurement of the combined boxes is precise to 1 cm.