the length of a string is known to be exactly 9.84cm. two students measured the string. student A used a ruler marked in centimeters and got a measurement of 10 cm. student B used a ruler marked in millimeters and centimeters and got a measurement of 9.8 cm. which student's measurement is more accurate? why?
The scale marked in mm will provide the more accurate measurement. Apparently, the student who used the ruler marked in cm rounded off the mesurement to the nearest cm, and did not even try to interpolate between the scale divisions.
To determine which student's measurement is more accurate, let's compare their measurements to the known length of the string.
Student A used a ruler marked in centimeters and measured the string to be 10 cm. Since we know the actual length of the string is 9.84 cm, student A's measurement is slightly longer than the actual length.
Student B used a ruler marked in millimeters and centimeters and measured the string to be 9.8 cm. Comparing this to the actual length of 9.84 cm, student B's measurement is slightly shorter than the actual length.
Based on these comparisons, we can conclude that student B's measurement is closer to the actual length of the string. Therefore, student B's measurement can be considered more accurate.
The reason student B's measurement is more accurate is because the ruler they used had a finer scale, marked in millimeters. This finer scale allows for more precise measurements, resulting in a measurement that is closer to the actual length. Student A's ruler only had markings in centimeters, which are larger units and therefore have a larger margin of error.