Two students measure the length of the same steel rod whose accepted value is 50.00 cm
PHYSICS · Multi-part · A Level · Physics · Measurements and their errors · Measurements and their errors
Problem
Two students measure the length of the same steel rod whose accepted value is 50.00 cm. Their five independent readings are recorded below:
Student A: 49.8 cm, 50.2 cm, 50.1 cm, 49.9 cm, 50.0 cm
Student B: 48.2 cm, 51.6 cm, 50.4 cm, 49.7 cm, 50.1 cm
Answer the following questions, showing each result to the correct number of significant figures.
(i) Calculate the mean length obtained by each student.
(ii) Determine the absolute error of the mean value for each student relative to the accepted value.
(iii) Express the error of each student as a percentage error.
(iv) For each student, find the range (difference between highest and lowest reading) and use it as a simple indicator of precision.
(v) On the basis of your calculations, state whose measurements are more accurate and whose are more precise, giving clear reasons.