More minor wording changes in Quantities tutorial

Author: eteq

tutorials/Quantities/Quantities.ipynb

@@ -287,7 +287,7 @@
      "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "Now for the actual mass calculation.  If a galaxy is pressure-supported (for example, and elliptical or dwarf spheroidal galaxy), its mass within the stellar extent can be estimated using a straightforward formula: $M_{1/2}=4\\sigma^2 R_{eff}/G$.  There are caveats to the use of this formula for science - see Wolf et al. 2010 for details.  For demonstrating `Quantity`, just accept that this is often good enough. For the calculation we can just multiply the quantities together, and `astropy` will keep track of the units."
+      "Now for the actual mass calculation.  If a galaxy is pressure-supported (for example, an elliptical or dwarf spheroidal galaxy), its mass within the stellar extent can be estimated using a straightforward formula: $M_{1/2}=4\\sigma^2 R_{eff}/G$.  There are caveats to the use of this formula for science - see Wolf et al. 2010 for details.  For demonstrating `Quantity`, just accept that this is often good enough. For the calculation we can just multiply the quantities together, and `astropy` will keep track of the units."
      ]
     },
     {
@@ -970,7 +970,7 @@
      "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "The funding agency is impressed at your resolution, and your instrument is saved.  You now go on to win the Nobel Prize due to discoveries the instrument makes.  And it was all because you used `Quantity` as the input of code you shared."
+      "The funding agency is impressed at the resolution you achieved, and your instrument is saved.  You now go on to win the Nobel Prize due to discoveries the instrument makes.  And it was all because you used `Quantity` as the input of code you shared."
      ]
     }
    ],