## Essential University Physics: Volume 1 (3rd Edition)

We first find the value of Q: $Q_h = \frac{2\times 10^{11}}{.33}=6.06\times10^{11}$ Thus, it follows: $Q_c= 6.06\times10^{11}-2\times10^{11}=4.06\times10^{11}$ We now find: $m = \frac{4.06\times10^{11}}{4184\times5}= 1.94 \times 10^7$ Thus, the answer is: $= 1.94\times10^7-1.8\times10^7=1.4\times10^6$