Transcript File
The line falls between 23.1 and 23.2 The measurement extends between 23.1 and 23.2 23.1? Therefore, we can be sure the measurement is 23.1? This is where “estimation” comes into play… Person 1 2 3 4 5 Measurement (cm) st two numbers 1 1.25 (1.2_) are certain. 1.26 1.24 Last number is 1.25 (1.2?) uncertain. 1.26 Every measurement REQUIRES only 1 estimation!!! Significant Figures Practice Determine the number of significant figures in… 3.05 g Significant Figures Practice Determine the number of significant figures in… 3.05 g 3 Sig figs! Significant Figures Practice Determine the number of significant figures in… 600 g Significant Figures Practice Determine the number of significant figures in… 600 g 1 Sig fig! Significant Figures Practice Determine the number of significant figures in… 0.9280 s Significant Figures Practice Determine the number of significant figures in… 0.9280 s 4 Sig figs! Significant Figures Practice Determine the number of significant figures in… 0.0006 mm Significant Figures Practice Determine the number of significant figures in… 0.0006 mm 1 Sig fig! Significant Figures Practice Determine the number of significant figures in… 5000 kg Significant Figures Practice Determine the number of significant figures in… 5000 kg 1 Sig fig! Significant Figures Practice Determine the number of significant figures in… 8 3.0 x 10 m/s Significant Figures Practice Determine the number of significant figures in… 8 3.0 x 10 m/s 2 Sig figs! Significant Figures Practice Round each value to two significant figures. 78.9 m Significant Figures Practice Round each value to two significant figures. 78.9 m 79 m Significant Figures Practice Round each value to two significant figures. 135947 km Significant Figures Practice Round each value to two significant figures. 135947 km 140000 km 5 Or 1.4 x 10 km Completely missed the dartboard!!! I have a splitting headache… • Refers how close a measurement is to the actual (true) value. • Dartboard Analogy: The bull’s eye is the actual point where a person is aiming for. 100g Accurate • “correct”. A measurement is considered accurate if correctly reflects the size of the object being measured. • How close are you to the actual/accepted value? • Does the practice of using body parts as measurement tools produce accurate results? • Refers how close a a group of measurements are to one another. (reproducibility) Person 1 2 3 4 5 Measurement (cm) 1.25 1.26 1.24 1.25 1.26 Precise • A precise measurement is repeatable and reliable. Getting the same measurement each time. • Does the practice of using body parts as measurement tools produce precise measurements? (were all of your results the same?) Accurate or precise? Accurate and Precise! Accurate or Precise? Accurate Accurate or Precise? Accurate • We can never get a perfect measurement, the best that we can do is get as close as possible within the limitations of our measuring instruments. Every measurement REQUIRES only 1 estimation!!!