A monkey is perched on a tree limb. The limb applies a normal force...

The total force exerted by the limb on the monkey is the resultant of the normal force and the frictional force.

Since the normal force and frictional force are perpendicular to each other, the magnitude of the total force $F$ is given by:

$F = \sqrt{N^2 + f^2}$

Substituting the given values $N = 48 \text{ N}$ and $f = 20 \text{ N}$:

$F = \sqrt{48^2 + 20^2}$

$F = \sqrt{2304 + 400}$

$F = \sqrt{2704} = 52 \text{ N}$