Problem $4$: $(7\%$ of Assignment Value$)$

A $72\mathrm{.}8$ kg man stands on his toes by exerting an upward force through the Achilles tendon, as shown in the figure.

Part $($a$)$

In units of newtons, what is the magnitude of the force through the Achilles tendon if he stands on one foot?

Part $($b$)$

Calculate the force in units of newtons at the pivot of the simplified lever system shown. That force is representative of forces in the ankle joint.

$F_P=$ N