During a weight training session, a person is performing a knee extension exercise with a $100$N

weight acting at the ankle. What is the quadriceps torque necessary to maintain a knee joint

angle of $-60$ degrees relative to the right horizontal passing through the knee joint? Given:

weight of shank and foot $=10$ N$,$ shank length $=0\mathrm{.}4$m $($point of application of the weight$),$ shank

and foot segment COM $=0\mathrm{.}15$m from the knee joint.

$20\mathrm{.}75$ Nm