1. Five persons are having a tug-of-war. Kurt and Brian are on the left; Amy, Barbara, and Joyce are on the right. Amy pulls with a force of 225 N, Barbara pulls with a force of 495 N, Joyce pulls with a force of 455 N, and Kurt pulls with a force of 605 N. With what force must Brian pull to produce equilibrium?
2. A certain wire can support 6450 lb before it breaks. Seven 820-lb weights are suspended from the wire. Can the wire support an eighth weight of 820 lb?
3. The frictional force of a loaded pallet in a warehouse is 385 lb. Can three workers, each exerting a force of 135 lb, push it to the side?
4. A bridge has a weight limit of 7.0 tons. How heavy a load can a 2.5-ton truck carry across?
5. A tractor transmission weighing 260 N and a steering gear box weighing 62.0 N are on a workbench. What upward force must the bench exert to maintain equilibrium?
6. A skid loader lifts a compressor weighing 672 N and a hose weighing 26.0 N. What upward force must the loader exert to maintain equilibrium?