Question:
A monkey is sitting on a tree limb. The limb exerts a normal force of $48 \mathrm{~N}$ and a frictional force of 20 $\mathrm{N}$. Find the magnitude of the total force exerted by the limb on the monkey.
Solution:
$F_{N}=48 \mathrm{~N}$ and $F_{F}=20 \mathrm{~N}$
$F_{R}=\sqrt{F_{N}^{2}+F_{F}^{2}}$
$F_{R}=\sqrt{48^{2}+20^{2}}$
$F_{R}=52 \mathrm{~N}$