Hw1  problem V. part 7 (g).  comparative force: 1μF capacitor with 1V charge

ClearAll[volt, farad,  meter, cm, micron, hbar, c]
volt = Quantity[1, "volts"];
farad = Quantity[ 1, "Farads"];
meter = Quantity[1, "meters"];
cm = 10^(-2) meter;
micron = Quantity[10^(-6), "meters"];
hbar = WolframAlpha["reduced Planck constant SI units",{{"Result",1},"QuantityData"}];
c = WolframAlpha["convert speed of light to m/s",{{"Result",1},"QuantityData"}];

ClearAll[ fCasimir, fCapacitor]
fCasimir[a_, area_] := UnitConvert[ -Pi^2 hbar c area/(1440 a^4), "Newtons"]
fCapacitor[a_, capacitance_, volts_] := UnitConvert[ capacitance * volts^2 /a, "Newtons"]

casimirValue = fCasimir[1 micron, (1 cm)^2]
capValue = fCapacitor[1 micron, 10^(-6) farad, 1 volt] 
capValue/casimirValue