Since the floor is rough, it exerts both a normal force

N$1$

and a frictional force

f$1$

on the ladder. However, since the wall is frictionless, it exerts only a normal force

N$2$

on the ladder. The ladder has a length of

L $=4\mathrm{.}7$ m$,$

a weight of

WL $=62\mathrm{.}0$ N$,$

and rests against the wall a distance

d $=3\mathrm{.}75$ m

above the floor. If a person with a mass of

m $=90$ kg

is standing on the ladder, determine the following.

$($a$)$ the forces exerted on the ladder when the person is halfway up the ladder $($Enter the magnitude only.$)$

N$1=$ NN$2=$ Nf$1=$ N

$($b$)$ the forces exerted on the ladder when the person is three$-$fourths of the way up the ladder $($Enter the magnitude only.$)$

N$1=$ NN$2=$ Nf$1=$ N