Table 1 Measured diameters D1 and D2 of the concentric diffraction rings as function of the accelerating voltage U. U/kV D₁/cm D₂/cm 3.0 3.0 5.0 3.5 2.9 4.7 4.0 2.8 4.5 4.5 2.6 4.2 5.0 2.4 4.0 Determination of lattice plane spacings of graphite 1. Plot the experimental data D₁ versus 1/√U and D2 versus 1/√ on the same coordinate axes. 2. Fit the dependences by straight lines passing through the origin. Denote ki and k₂ the slopes. 3. Calculate the estimated standard deviations in the slopes, Ak₁ and Aly 4. Calculate d₁ and d2 by use of Eq. (11), where k is substituted by ki and k₂. 5. Use Aki and Ak2 to calculate the estimated standard deviations in d₁ and d₂, respectively. Follow through the analysis carefully, and be sure to use the correct procedure as you change the estimated standard deviation in 1/d to that in d. 8. Write the final results (best estimate estimated standard deviation) and compare the experimental values for the spacings to the accepted values. Useful physical constants: h=6.626 070 15 x 10-34 J Hz-1 e=1.602 176 634 × 10-19 C m = 9.109 383 7015(28) x 10-31 kg