c
$\overrightarrow{\mathrm{F}}_{\mathrm{SR}}=-\overrightarrow{\mathrm{F}}_{\mathrm{PQ}}$
$\overrightarrow{\mathrm{F}}_{\mathrm{SR}}+\overrightarrow{\mathrm{F}}_{\mathrm{PQ}}=0$
$\overrightarrow{\mathrm{F}}_{\mathrm{SP}}=\mathrm{B}_{0}\left(5+\frac{\mathrm{O}}{\ell}\right) \mathrm{I} \ell=5 \mathrm{B}_{0} \mathrm{I}_{\ell}(-\hat{\mathrm{i}})$
$\overrightarrow{\mathrm{F}}_{\mathrm{QR}}=\mathrm{B}_{0}\left(5+\frac{\ell}{\ell}\right) \mathrm{I} \ell=6 \mathrm{B}_{0} \mathrm{I} \ell(+\hat{1})$
$\overrightarrow{\mathrm{F}}_{\mathrm{net}}=\overrightarrow{\mathrm{F}}_{\mathrm{SP}}+\overrightarrow{\mathrm{F}}_{\mathrm{QR}}=6 \mathrm{B}_{0} \mathrm{I} \ell(\hat{\mathrm{I}})+5 \mathrm{B}_{0} \mathrm{I} \ell(-\hat{\mathrm{I}})=\mathrm{B}_{0} \mathrm{I} \ell(\hat{\mathrm{I}})$
