Problem $7\mathrm{.}15$

A sadistic carnival operator has designed a ride based on a fourbar linkage, shown in Figure $7\mathrm{.}141.$ The passenger sits at point $\backslash ($ P $\backslash )$ while the crank rotates at a constant $40$ rpm $.$ The thickness of all links is $25$ mm $,$ and all links are made of aluminum. Assume that the rider is a point mass of $100$ kg located at point $\backslash ($ P $\backslash ).$ The distance between ground pins is $1200$ mm $.$ Calculate and plot the forces in the $\backslash ($ x $\backslash )$ and $\backslash ($ y $\backslash )$ direction at the crank pivot, and the driving torque required to operate the ride. Do not ignore gravity.

FIGURE $7\mathrm{.}141$

Problem $7\mathrm{.}15.$