Lab:Measurement Error (Bounds) Purpose The purpose of this experiment was to understand and recognize that errors do occur when doing experiments and making measurements. With this lab we had to understand how to analyze the data using measurement bounds. Theory: In this experiment we were to find the density of the wood we are measuring by using the method of upper bound and lower bound. Density is a physical property of matter. Every element and compound has its very own unique density associated with it.
Density can be defined in a qualitative manner as the measure of the relative heaviness of objects with a constant volume or also as the amount per unit size. Apparatus In this experiment we used four apparatuses. We used 1 rectangular block of wood , 1 triple beam balance calibrated , 1 meter stick and 1 micrometer. Procedure In this experiment the first step we did was measured the block of wood’s length, width and height using the meter stick or the micrometer. Next we recorded the lower bound, upper bound and our best estimate for the length, width and height of the block of wood.
We also repeated this step to find the mass of the block using the triple beam balance. Next we were to find the density of the block of wood. My lab partners and I found the density for the lower bound , upper bound and for our best estimate. Data Measurements of the Wood Block and Cylinder Analysis After finding all the measurements needed next we did our calculations to find the density using this equation: d = m/ v First we found the density for our best estimate. Using only the best estimate data. Mass= 2. 3225kg Height=. 1376m Width=. 0190m Length = . 235m (2. 3225kg)/ (. 235m*. 019m*. 1376m)= 378. 1 kg/m^3
Next we found the density for our upper bound. Using the mass from the upper bound and the volume from the lower bound. Mass: 2. 323kg Height=. 14m Width=. 0194m Length=. 24cm (2. 323kg)/( . 230m*. 0188m*. 1374m)= . 391. 0 kg/m^3 After founding the upper bound density we found the lower bound density. Using the lower bound and the upper bound volume. Mass= 2. 3225kg Height=. 1374m Width=. 0188m Length= . 23m (. 23225)/(. 240m*. 0194m*. 140m)= . 356. 3 kg/m^3 After finding all three densities next we were suppose to find the error between the upper bound , lower bound and best estimate. Upper bound – Best estimate: 391. 0-. 378. 1= 12. Best Estimate – Lower Bound: 378. 1-356. 3= 21. 8 My lab partners and I reported that density of our block of wood is 378. 1+/-21. 8 Conclusion: In this experiment my lab partners and I learn that in every experiment there is always human error and uncertainties. When starting this lab we were suppose to find the density of wood , but while finding the density of wood we also found that there is an error of +/- 21. 8 . I do believe that we were very successful in this experiment. The only thing I would suggest to be changed is the wood, because the wood we were using was chipped and a little unbalanced. ———————– [pic]