(Solved): Two children pull a third child on a snow saucer sled exerting forces \( F_{1} \) and \( F_{2} \) a ...

Two children pull a third child on a snow saucer sled exerting forces \( F_{1} \) and \( F_{2} \) as shown above in the figure. Find the acceleration \( a \) and direction \( \theta \) of the \( 42-\mathrm{kg} \) sled and child system. Note that the direction of the frictional force \( f \) is unspecified; it will be in the opposite direction of the sum of \( F_{1} \) and \( F_{2} \) Enter answer accurate to 4 significant figures. \[ \begin{array}{ll} a= & \mathrm{m} / \mathrm{s}^{2} \\ \theta= & \text { degrees } \end{array} \]