mistake when measuring and record a value that's too low, but becausc was measured, the mistake went on unnoticed. 1.4.3 Measure the diameters of a few ball bearings of different sizes and estimaghe their volumes. Mention uncertainty in each result. analyze and evaluate the abrom experiment and suggest improvements. To measure the diameters of different-sized ball bearings and estimate their volumes, assume we have a caliper with a measurement uncertainty of \( \pm 0.01 \mathrm{~mm} \). Here's an example of measuring three ball bearings and estimating their volumes: Ball Bearing 1: Diameter measurement: \( 5.12 \mathrm{~mm} \pm 0.01 \mathrm{~mm} \) (using the caliper) \[ \begin{array}{c} \text { Radius }=\frac{\text { diameter } 5}{2}=2.56 \mathrm{~mm} \pm 0.005 \mathrm{~mm}=r+\Delta r \\ \text { Volume }=\frac{4}{3} \pi r^{3}=\frac{4}{3} \pi(r+\Delta r)^{3} \end{array} \] \( \therefore \Delta r \) is very small as compared to \( r \) so therefore square and higher power will be neglected \[ \begin{array}{c} \text { Volume }=\frac{4}{3} \pi r^{3} \pm 4 \pi r^{2} \Delta r \\ \left.V \pm \Delta V=\frac{4}{3}(3.14)(2.56)^{3} \pm 4(3.14)(2.56)^{2}(0.005)\right) \\ =(70.24 \pm 0.41) \mathrm{mm}^{3} \end{array} \] Volume of ball bearing 1 is found to be \( 70.24 \mathrm{~mm}^{3} \) with uncertainty of \( 0.41 \mathrm{~mm}^{3} \) Ball Bearing 2: \[ \begin{array}{c} \text { Diameter measurement: } 3.78 \mathrm{~mm} \pm 0.01 \mathrm{~mm} \\ \text { Radius }=\text { diameter } / 2=1.89 \mathrm{~mm} \pm 0.005 \mathrm{~mm} \\ V \pm \Delta V=\frac{4}{3} \pi r^{3} \pm 4 \pi r^{2} \Delta r \\ V \pm \Delta V=(28.26 \pm 0.22) \mathrm{mm}^{3} \end{array} \] Volume of ball bearing 2 is found to be \( 28.26 \mathrm{~mm}^{3} \) with uncertainty of \( 0.22 \mathrm{~mm}^{3} \) Ball Bearing 3: \[ \begin{array}{c} \text { Diameter measurement: } 7.25 \mathrm{~mm} \pm 0.01 \mathrm{~mm} \\ \text { Radius }=\text { diameter } / 2=3.62 \mathrm{~mm} \pm 0.005 \mathrm{~mm} \\ V \pm \Delta V=\frac{4}{3} \pi r^{3} \pm 4 \pi r^{2} \Delta r \\ V \pm \Delta V=(198.60 \pm 0.82) \mathrm{mm}^{3} \end{array} \] Volume of ball bearing 3 is found to be \( 198.60 \mathrm{~mm}^{3} \) with uncertainty of \( 0.82 \mathrm{~mm}^{3} \) 14
Added by Farman H.
Close
Step 1
Record the measurement with its uncertainty. For example, if the caliper reads 5.12 mm, the measurement is 5.12 mm ± 0.01 mm. Show more…
Show all steps
Your feedback will help us improve your experience
Madhur L and 69 other Physics 103 educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Digital Measurements: Record all displayed digits and decimal places; Estimate the uncertainty using the largest of: the manufacturer's specification, the size of the fluctuations in the display, the value of 1 in the last displayed decimal place (for example, a mass of 23.82 grams would have an uncertainty of ± 0.01 gram.) 1. A digital balance displays a mass of 0.1243 grams. In grams, what is the size of the uncertainty? Analog Measurements: Estimate the first uncertain digit in the reading by estimating its distance between the smallest marked lines on the device. Mentally split the space between the marks into 2, 5, or 10 smaller divisions, convert this to a decimal, and record your answer using this as the final decimal place. The uncertainty in the reading is the size of your mental divisions. (Your instructor may require evidence for your answers to questions 2-4 below) 2. A ruler shows a measurement of length between 2.2 and 2.3 cm. The marks are closely spaced and you can imagine only one line between the two marked divisions. Record the length and the uncertainty in cm as a confidence interval, using ± format: 3. A volume measurement is made in a cylinder with marks every 1 mL. You observe the volume is between 48 and 49 mL, and you estimate that it is about two-fifths of the way between the marks. Record the volume and the uncertainty in mL: 4. A volume measurement is made in a beaker with marks every 20 mL. The volume is between 20 and 40 mL and you estimate that it is about three-tenths of the way between the marks. Record the volume and the uncertainty and the units: Calculated answers: Express the uncertainty to 1 significant figure, then round off the answer into the same decimal place as the uncertainty. Include units. 5. A calculation gave a density of 1.024666 g/mL and an uncertainty of 0.00333 g/mL. Re-express: Percent by mass solution: 6. You will prepare 40.0 grams of a NaCl solution that is 0.90% by mass. Calculate the mass of NaCl that is needed (show work on the back of this page), and record it in your lab notebook.
Dominador T.
Why do you think uncertainty in measurement occurs? Give at least two reasons [2 Points]. If x = 2.5 ± 0.1 cm and y = 3.1 ± 0.1 cm, and z = x + y, determine z0 and the upper bound of δz [1+1 = 2 Points]. z0 = x0 + y0 = 2.5 + 3.1 z0 = 5.6 cm. upper bound of δz = √(δx² + δy²) = √(0.1² + 0.1²) upper bound of δz = 0.14. 3. The volume of a cylinder is given by V = πr²l, where r is the radius and l is the length of the cylinder. If we measured r = 2.10 ± 0.05 cm, and l = 3.40 ± 0.05 cm, determine the uncertainty in volume. Show your calculation [Hint: Use Equation 4] [2 Points].
Bcrypt_Sha256$$2B$12$We1Wwocamog01O5I.V2Tkouxdh4Ofnmgpwkor7Leaonfpu0Ubfpua B.
Recommended Textbooks
University Physics with Modern Physics
Physics: Principles with Applications
Fundamentals of Physics
Watch the video solution with this free unlock.
EMAIL
PASSWORD