Neco 2018 Physics Question 1

A wooden block is supplied with a certified length of 150.00 mm. Using a metre rule (least count = 1 mm) and a vernier caliper (least count = 0.02 mm) you are to determine the length of the block and assess the reliability of the measurements. Three successive readings are taken with each instrument as shown in the table below. | Instrument | Reading 1 (mm) | Reading 2 (mm) | Reading 3 (mm) | |------------|----------------|----------------|----------------| | Metre rule | 149.8 | 150.2 | 150.0 | | Vernier caliper | 150.12 | 150.08 | 150.10 | Answer the following: a) Calculate the average length obtained with the metre rule and state its absolute uncertainty. b) Calculate the average length obtained with the vernier caliper and state its absolute uncertainty. c) Using the true length (150.00 mm) compute the percent error for each instrument. State whether each measurement is acceptable if the acceptable limit is ±0.5% of the true length.