1 AP Physics Statics Practice Test Answers: A,B,A,E,D,A,A,B,B,E,B,E ...

AP Physics Statics Practice TestAnswers: A,B,A,E,D,A,A,B,B,E,B,E 13. (a) R, (b) 0.78, (c) 3.8, (d) 5.63 14. (b) 882, (c) 151, (d) 0.17Directions: Answer the multiple choice questions in the space provided, 2 points each. Answer thewritten problems on this sheet. Show all of your work for the most credit. Use g = 9.8 m/s 2 . Circlepage number 2 for 2 points._____1. Determine the x and y components of F 3 so that the horizontal system shown below is in staticequilibrium.+YF 2=100NF 1=60N20 o 35 o+XA. F 3x = 44.8 N, F 3y = -68.6 N.B. F 3x = 143.1 N, F 3y = -68.6 N.C. F 3x = -68.6 N, F 3y = 44.8 N.D. F 3x = -44.8 N, F 3y = 68.6 N.E. F 3x = 44.8 N, F 3y = -143.1 N._____2. For the wheel-and-axle system shown below right, which of thefollowing expresses the condition required for the system to be instatic equilibrium?(A) m 1 = m 2 (B) am 1 = bm 2 (C) am 2 = bm 1(D) a 2 m l = b 2 m 2 (E) b 2 m 1 = a 2 m 2_____3. A square piece of plywood on a horizontal tabletop is subjected to the two horizontal forcesshown above. Where should a third force of magnitude 5 newtons be applied to put the piece ofplywood into equilibrium?1

_____4. Calculate the x and y coordinates of the center of mass of the system of particles shownbelow. M1 = 5.6 kg, M2 = 8.1 kg, M3 = 2.3 kgA. x = 2.30 m, y = 2.96 mB. x = 2.26 m, y = 3.01 mC. x = 2.21 m, y = 3.06 mD. x = 2.17 m, y = 2.91 mE. x = 2.29 m, y = 3.13 m_____ 5. A 100-newton weight is suspended by two cords as shown in the figure below. The tension inthe slanted cord is(A) 50 N (B) 100 N (C) 150 N ( D) 200 N (E) 250 N_____ 6. A piece of wire of uniform cross section is bent in the shape shown above. What are thecoordinates( x, y) of the center of mass?(A) (15/14, 6/7) (B) (6/7, 6/7) (C) (15/14, 8/7) (D) (1,1) (E) (1,6/7)2

_____7. The diagram below depicts a system in static equilibrium. θ1 = 35 o , θ2 = 65 o , and M = 262kg. The tension T1 is most nearly! 1 ! 2T1 T2A. 1101.8 N.B. 568.4 N.C. 441.6 N.D. 2135.7 N.E. 922.6 N.M_____8. The tension T2 in the above problem is most nearlyA. 1416.7 N.B. 2135.7 N.C. 568.4 N.D. 1101.8 N.E. 855.9 N._____ 9. A block of mass 5 kilograms lies on an inclined plane, as shown below. The horizontal andvertical supports for the plane have lengths of 4 meters and 3 meters, respectively. The coefficientof friction between the plane and the block is 0.3. The magnitude of the force F necessary to pullthe block up the plane with constant speed is most nearly(A) 30 N (B) 42 N (C) 49 N(D) 50 N (E) 58 N3

_____10. A rod of negligible mass is pivoted at a point that is off-center, so that length l 1 is differentfrom length l 2 . The figures above show two cases in which masses are suspended from the ends ofthe rod. In each case the unknown mass m is balanced by a known mass, M 1 or M 2 , so that the rodremains horizontal. What is the value of m in terms of the known masses?(A) M l + M 2 (B) ½(M l + M 2 ) (C) M lM 2 (D) ½M 1 M 2 (E) M 1M 2!_____11. Calculate the mass M1 for the system shown below to be balanced. L1 = 3.0 m, L2 = 1.5 m,L3 = 3.5 m, M2 = 45 kg, M3 = 28 kg. The mass of the board is 80 kg, the length of the board is 8 m,and L3 is measured from the fulcrum to the right end of the board.L3L1M1 L2 M2 M3A. 25.0 kg.B. 41.8 kg.C. 55.2 kg.D. 125.5 kg.E. 165.5 kg.______12. The Normal force of the fulcrum on the board in the above problem isA. 1744 N.B. 1500 N.C. 1125 N.D. 2040 N.E. 1909 N.4

13. (10 Points) Two identical 30 kg beams are attached to a hinge on the wall. A cable is attached tothe end of each beam so that it is in static equilibrium as shown below. Each beam is 2 m long.θ A = 35 o , θ B = 20 o , and θ C = 50 o 1The rotational inertia of the rod about its end is3 ml2 .!(a) Predict which cable will have the greatest tension, the cable on the left or on the right? Justify youranswer.(b) Solve for the ratio of the cable tension on the left beam to the cable tension on the right beam.(c) The cable on the left is severed and the beam starts to swing. What is its angular velocity when it isin a vertical position?(d) The cable on the right is severed. What is the initial angular acceleration of the beam?5

14. (10 Points) A ladder is leaning against a frictionless wall as shown below. The ladder has a mass of30 kg and is 5 m long. A 60 kg person is 1.5 m from the bottom of the ladder. You must show all yourwork for credit.(a) Draw a free-body diagram of the ladder and draw and label all the forces acting on it.(b) Solve for the normal force of the ground on the ladder.(c) Solve the force of the wall on the ladder.(d) Solve for minimum coefficient of static friction between the ladder and the ground for the systemto be in static equilibrium.6