The helicopter view in Fig. P 3.29 shows two people pulling on a stubborn mule. The person on the right pulls with a force $\overrightarrow{\mathbf{F}}_{1}$ of magnitude 120 $\mathrm{N}$ and direction of $\theta_{1}=60.0^{\circ} .$ The person on the left pulls with a force $\overrightarrow{\mathbf{F}}_{2}$ of magnitude 80.0 $\mathrm{N}$ and direction of $\theta_{2}=75.0^{\circ} .$ Find (a) the single force that is equivalent to the two forces shown and (b) the force that a third person would have to exert on the mule to make the resultant force equal to zero. The forces are measured in units of newtons (symbolized N).