English: Plot of instantaneous efficiency (blue line) and overall efficiency (red line) as percentages of the engine efficiency for a rocket accelerating from rest. The overall efficiency is relationship of rocket energy to energy of consumed fuel: ${\displaystyle {\eta }_{\mathrm{o}\mathrm{v}}=\frac{E_{}}{E_{\mathrm{f}\mathrm{u}\mathrm{e}\mathrm{l}}}=\frac{m_{}{v}^2}{m_{\mathrm{f}\mathrm{u}\mathrm{e}\mathrm{l}}{v}_{\mathrm{e}}^2}=\frac{m_{}{v}^2}{\left(e^{\frac{v}{v_{\mathrm{e}}}}{m}_{}-m_{}\right)v_{\mathrm{e}}^2}=\frac{1}{e^{\frac{v}{v_{\mathrm{e}}}}-1}{\left(\frac{v}{v_{\mathrm{e}}}\right)}^2}$