An object is suspended from two cables that meet at a point above the object. One cable pulls with a force modeled by F1 = −77i + 35j. The other cable pulls with a force modeled by F2 = 92i + 84j. What is the angle between the cables? Round to the nearest degree. a 119° b 71° c 105° d 113°

F = (-30i + 60j + 60k )kN %3D Forces are concurrent at point O. Determine the magnitude of the resultant of the three vectors. a 71.5 kN b 187 kN F, = (60i – 20j+ 15k )kN c 116 kN d 83.7 kN Determine the angle between F, andF,. F, = (20j – 25k)kN X а 111° b 132° c 69.0° d 21.0° Select the expression that denotes a unit vector in the direction and sense of F,. a 0.625j -0.781k b 0.625i -0.781j c -0.625 j –0.781k d 0.625i +0.781j

The force F has a magnitude of 480 Ib and acts along the diagonal of the parallelepiped as shown. Express Fin terms of its magnitude times the appropriate unit vector and determine its x-, y-, and z-components. A 6' F = 480 b 8' 3' B Answers: i+ i j+ i F= ( i Ib)( i Fx Ib i Fy Ib F2 Ib i

The figure below shows a bird feeder that weighs 101.1 N. The feeder is supported by a vertical wire, which is in turn tied to two wires, each of which is attached to a horizontal support. The left wire makes a 60° angle with the support, while the right wire makes a 30° angle. What is the tension in each wire (in N)?   A bird feeder is suspended from a vertical wire. The top of the wire is tied to two other wires. The left and right wires go up and to the left and up and to the right, respectively, from the connection point to a horizontal support. The left wire makes an angle of 60° with the support. The right wire makes an angle of 30° with the support. left wire Nright wire Nbottom wire N