## College Physics (4th Edition)

A force of $98.0~N$ must be applied to lift the load.
To lift the load, the torque exerted by the applied force about the fulcrum must be equal in magnitude to the torque exerted by the load's weight about the fulcrum. We can find the applied force $F_a$: $r_a~F_a = r_l~F_l$ $F_a = \frac{r_l~F_l}{r_a}$ $F_a = \frac{r_l~mg}{r_a}$ $F_a = \frac{(1.2~m)(20.0~kg)(9.80~m/s^2)}{2.4~m}$ $F_a = 98.0~N$ A force of $98.0~N$ must be applied to lift the load.