Physics Midterm Final Exam Review Study Guide

AP Physics 1st Semester Final Exam Review 1. The graph at the right shows the velocity v as a function of time t for an object moving in a straight line. Which of the following graphs shows the corresponding position x as a function of time t for the same time interval? v t x x (A) x (B) t x t (D) 3. 4. (E) t t 2 – 3 At time t = 0, car X traveling with speed v0 passes car Y. which is just starting to move. Both cars then travel on two parallel lanes on the same straight road. The graphs of speed v versus time t for both cars are shown above. 2. x (C) Which of the following is true at time t = 20 seconds? (A) Car Y is behind car X. (B) Car Y is passing car X. (C) Car Y is in front of car X. (D) Both cars have the same acceleration. (E) Car X is accelerating faster then car Y. From time t = 0 to time t = 40 seconds, the areas under both curves are equal. Therefore, which of the following is true at time t = 40 seconds? (A) Car Y is behind car X. (B) Car Y is passing car X. (C) Car Y is in front of car X. (D) Both cars have the same acceleration. (E) Car X is accelerating faster than car Y. t v Car Y Car X v0 t (s) 0 10 20 30 40 A body moving in the positive x direction passes the origin at time t = 0. Between t = 0 and t = 1 second, the body has a constant speed of 24 meters per second. At t = 1 second, the body is given a constant acceleration of 6 meters per second squared in the negative x direction. The position x of the body at t = 11 seconds is (A) +99 m (B) +36 m (C) –36 m (D) –75 m (E) –99 m AP Physics 1st Semester Final Exam Review 5. Page 2 Which of the following pairs of graphs shows the distance traveled versus time and the speed versus time for an object uniformly accelerated from rest? Distance Speed Distance (A) Speed (B) 0 t Distance 0 t Speed 0 t Distance (C) 0 t Speed (D) 0 t Distance 0 t 0 t 0 t Speed (E) 0 6. t 0 t A particle moves along the x-axis with a non-constant acceleration described by a = 12t, where a is in meters per second squared and t is in seconds. If the particle starts from rest so that its speed v and position x are zero when t = 0, where is it located when t = 2 seconds? (A) x = 12 m (B) x = 16 m (C) x = 24 m (D) x = 32 m (E) x = 48 m 7 – 8 An object moving in a straight line has a velocity v in meters per second that varies with time t in seconds according to the 2 following function: v = 4 + 0.5 t . 7. The instantaneous acceleration of the object at t = 2 seconds is 2 (A) 2 m/s 2 (B) 4 m/s 2 (C) 5 m/s 2 (D) 6 m/s 2 (E) 8 m/s 8. The displacement of the object between t = 0 and t = 6 seconds is (A) 22 m (B) 28 m (C) 40 m (D) 42 m (E) 60 m AP Physics 1st Semester Final Exam Review 9. Page 3 A 500-kilogram sports car accelerates uniformly from rest, reaching a speed of 30 meters per second in 6 seconds. During the 6 seconds, the car has traveled a distance of (A) 15 m (B) 30 m (C) 60 m (D) 90 m (E) 180 m 10. An object is shot vertically upward into the air with a positive initial velocity. Which of the following correctly describes the velocity and acceleration of the object at its maximum elevation? Velocity Acceleration (A) Positive Positive (B) Zero Zero (C) Negative Negative (D) Zero Negative (E)Positive Negative 11. Which of the following graphs of position d versus time t corresponds to the motion of an object moving in a straight line with positive acceleration? d d d t (A) d t (B) d t (C) t (D) t (E) 12. A ball is thrown straight up from a point 2 m above the ground. The ball reaches a height of 3 m above its starting point and then falls 5 m to the ground. When the ball hits the ground what is its displacement from its starting point? (A) 0 m (B) 8 m below (C) 5 m below (D) 2 m below (E) 3 m above 13. What do acceleration and velocity have in common? (A) Both are vectors. (B) Both are scalars. (C) Both are measured in units of distance divided by time. (D) Both are measured in units of distance divided by time squared. (E) They are different names for the same quantity. AP Physics 1st Semester Final Exam Review Page 4 14. In the absence of air friction, an object dropped near the surface of the Earth experiences a constant acceleration of about 10 2 m/s . This means that the: A) Speed of the object increases 10 m/s during each second. B) Speed of the object as it falls is 10 m/s. C) Object falls 10 meters during each second. D) Object falls 10 meters during the first second only. 2 E) Derivative with respect to time for the object equals 10 m/s . vf vi 15. A ball initially moves horizontally with a velocity vi as shown above. It is then struck by a stick. After leaving the stick, the ball moves vertically with a velocity vf, which is smaller in magnitude than vi. Which of the following vectors best represents the direction of the average acceleration experienced by the ball? (A) (B) (C) (D) (E) 16. At a particular instant, a stationary observer on the ground sees a package falling with a speed v1 at an angel to the vertical. To a pilot flying horizontally at a constant speed relative to the ground, the package appears to be falling vertically with a speed v2 at that instant. What is the speed of the pilot relative to the ground? A) v1 + v2 B) v1 – v2 C) v2 – v1 D) v1  v2 E) v1  v2 2 2 2 2 17. A spring loaded gun can fire a projectile to a height h if it is fired straight up. If the same gun is pointed at an angle of 45° from the vertical, what maximum height can now be reached by the projectile? (A) h 4 (B) h 2 2 (C) h 2 (D) h 2 (E) h 18. Two people are in a boat that is capable of a maximum speed of 5 kilometers per hour in still water and wish to cross a river 1 kilometer wide to a point directly across from their starting point. If the speed of the water is in the river is 5 kilometers per hour, how much time is required for the crossing? A) 1/20 hr B) 1/10 hr C) 1 hr D) 10 hr E) The point directly across from the starting point cannot be reached under these conditions. AP Physics 1st Semester Final Exam Review Page 5 19. A projectile fired from the surface of the Earth with a speed of 200 meters per second at an angle of 30° above the horizontal. If the ground is level, what is the maximum height reached by the projectile? A) 5 m B) 10 m C) 500 m D) 1,000 m E) 2,000 m 20. Vectors v1 and v2 shown at the right have equal magnitudes. The vectors represent the velocities of an object at times t1 and t2 respectively. The average acceleration of the object between time t1 and t2 was: A) Zero B) Directed north C) Directed west D) Directed north of east E) Directed north of west N N v2 v1 W E W E S S 21. A rock is dropped from the top of a 45-meter tower and at the same time, a ball is thrown from the top of the tower in a horizontal direction. Air resistance is negligible. The ball and the rock hit the level ground a distance of 30 meters apart. The horizontal velocity of the ball is most nearly: A) 5 m/s B) 10 m/s C) 14.1 m/s D) 20 m/s E) 28.3 m/s A ball is thrown and follows a parabolic path, as shown at the right. Air friction is negligible. Point Q is the highest point on the path. 22. Which of the following best indicates the direction of the acceleration, if any of the ball at point Q? Q P There is no acceleration of the ball at point Q. (A) (B) (C) (D) (E) 23. Which of the following best indicated the direction of the resultant velocity at point P? (A) (B) (C) (D) (E) AP Physics 1st Semester Final Exam Review Page 6 5 m/s 10 m 24. An object slides off a roof 10 meters above the ground with an initial horizontal speed of 5 meters per second as shown above. The time between the object’s leaving the roof and hitting the ground is most nearly: 1 s 2 1 s B) 2 (C) 2 s (D) 2s (E) 5 2 s A) 25. A racing car is moving around the circular track of radius 300 meters as shown at the right. At the instant when the car’s velocity is directed due east, its acceleration is directed due south and N has a magnitude of 3 meters per square seconds. When viewed from above, the car is moving: A) clockwise at 30 m/s B) clockwise at 10 m/s W C) anticlockwise at 30 m/s D) anticlockwise at 10 m/s E) with a constant velocity View of track from above S E 26. A projectile has an initial velocity of magnitude v0 which makes an angle of θ0 with the horizontal. Air friction is negligible. All of the following are true at point P, the highest point of the trajectory, EXCEPT: A) The time required to reach P is given by t  v0 cos 0 / g B) The horizontal displacement has been v0 t cos 0 , where t is the time required to reach P. C) hm ax  (v0 sin  0 ) 2 / 2 g P D) The speed is v0 cos 0 E) The acceleration is g hmax v0 θ AP Physics 1st Semester Final Exam Review Page 7 27. A box is attached to a mass by a string over a pulley. If given a slight push and then released the box moves across the surface at a constant speed. What is the value of the frictional force between the box and the surface? A) 0.5 N B) 1.5 N C) 5.0 N D) 15 N E) 20 N v is constant 1.5 kg 0.5 kg 28. A descending elevator of mass 1,000 kg is uniformly decelerated to rest over a distance of 8 m by a cable in which the tension is 11,000 N. The speed v 0 of the elevator at the beginning of the 8 m descent is most nearly: (A) 4 m/s (B) 10 m/s (C) 13 m/s (D) 16 m/s (E) 21 m/s Cable v 1000 kg Elevator v = v0 8m v=0 29. A block of mass m is accelerated across a rough surface by a force of magnitude F that is exerted at an angle  with the horizontal, as shown above. The frictional force on the block exerted by the surface has magnitude f. What is the acceleration of the block? (A) F/m (B) Fcos /m (C) (F-f)/m (D) (Fcos-f)/m (E) (Fsin-mg)/m F  f m 30. If F1 is the magnitude of the force exerted by the Earth on a satellite in orbit about the Earth and F 2 is the magnitude of the force exerted by the satellite on the Earth, then which of the following is true? (A) F1 is much greater than F2. (B) F1 is slightly greater than F2 . (C) F1 is equal to F2. (D) F2 is slightly greater than F1. (E) F2 is much greater than F1. AP Physics 1st Semester Final Exam Review Page 8 31. Two 0.60-kilogram objects are connected by a thread that passes over a light, frictionless pulley, as shown above. The objects are initially held at rest. If a third object with a mass of 0.30 kilogram is added on top of one of the 0.60-kilogram objects as shown and the objects are released, the magnitude of the acceleration of the 0.30-kilogram object is most nearly: 2 (A) 10.0 m/s 2 (B) 6.0 m/s 2 (C) 3.0 m/s 2 (D) 2.0 m/s 2 (E) 1.0 m/s 0.30 kg 0.60 kg 0.60 kg 32. DP (mass 70 kg), riding in an elevator feels “normal” when (it says ‘feels’ normal not ‘is’ normal!): A) Not moving. B) Moving up at a constant speed. C) Moving down at a constant speed. D) A & B only are true. E) B & C only are true. F) All of the above are true. 33. During part of his trip, DP feels like his weight is 900 N. The floor is pushing up at: A) 0 N B) 200 N C) 700 N D) 900 N E) 1600 N 34. The value of the net force in the previous problem is then: A) 0 N B) 200 N C) 700 N D) 900 N E) 1600 N 35. A block of mass 5 kilograms lies at rest on an inclined plane, as shown above. The horizontal and vertical supports for the plane have lengths of 4 meters and 3 meters, respectively. The magnitude of the force F necessary to pull the block up the plane with constant speed is most nearly: (A) 30 N (B) 40 N (C) 49 N (D) 50 N (E) 58 N 36. When the frictionless system shown above is accelerated by an applied force of magnitude F, the tension in the string between the blocks is: (A) 2 F (B) F (C) (2/3)F (D) 0.5F (E) (1/3)F 2 kg F 5 kg 3m 4m 1 kg F AP Physics 1st Semester Final Exam Review Page 9 37. A mass m moves on a curved path from point X to point Y. Which of the following diagrams indicates a possible combination of the net force F on the mass, and the velocity v and acceleration a of the mass at the location shown? Y Y F v F Y a m m m a v X Y (A) v X F X a (D) X Y (B) (C) v v m F a m X a F (E) 38. Two blocks are pushed along a horizontal frictionless surface by a force of 20 Newtons to the right, as shown above. The force that the 2-kilogram block exerts on the 3-kilogram block is: (A) 8 Newtons to the left. (B) 8 Newtons to the right. (C) 10 Newtons to the left. (D) 12 Newtons to the right. (E) 20 Newtons to the left. 39. A 100-newton weight is suspended by two cords as shown in the figure above. The tension in t slanted cord is: (A) 50 N (B) 100 N (C) 150 N (D) 200 N (E) 250 N 20 N 3 kg 2 kg 30 100 N AP Physics 1st Semester Final Exam Review Page 10 40. The parabola above is a graph of speed v as a function of time t for an object. Which of the following graphs best represents the magnitude F of the net force exerted on the object as a function of time t? v vt F F t t (A) F t (B) F F t (C) t (D) (E) Neglect all air friction for this problem only. The mass ‘m’ moves in a horizontal circle of radius ‘r’ in the time ‘T’  41. The number of forces acting on the mass is most nearly: (A) 1 (B) 2 (C) 3 (D) 4 (E) 5 42. The acceleration of the object is given by which of the following? (A) 2r (B) 2r T (C) 4 2 r T2 (D) tan  (E) g 43. The tension in the string is given by which of the following? (A) mg (B) mg tan  (C) mg (1  tan 2 ) 1 2 (D) mv 2 r t (E) mg sin  2 AP Physics 1st Semester Final Exam Review Page 11 44. An expression for the minimum speed a roller coaster car of mass ‘m’ can have and make the loop of radius ‘R’ is most nearly: A) B) C) R mr mgr rg D) 4 2 gT 2 E) rg 45. Riding on the people mover, DP (mass = 70 kg) and his friends are attempting to “surf” that is ride without holding on. From rest the people mover accelerates forward to compensate DP must: (A) Lean in the direction of the acceleration. (B) Lean toward the center of the car. (C) Lean toward the back of the car. (D) Lean toward the outside of the car. (E) Stand straight up. 46. The angle of lean is given by which of the following?  v2  tan 1    rg  1  g  (B) tan   a 2 1  v   (C) sin   r  (A)  N   cos1   mg  1 (E) tan   (D) 47. If the people mover is accelerating with acceleration equal to ‘a’ the total force exerted by the floor on DP in most nearly: (A) mg (B) Fc (C) m g  a c  (D) mg 2  Fc2 (E) (mg ) 2  f 2 AP Physics 1st Semester Final Exam Review Page 12 48. A block accelerates down a ramp as shown. Which of the following is NOT true? A) N  mg cos a  g sin   g cos g sin  C)   g cos D) f  mg cos E) Fnet  mg sin   mg cos B) θ 49. Which expression below correctly relates the coefficient of friction and the “critical angle” – the angle that you could raise the ramp to so that the block just starts to slide? A)   g cos B) C) D) E)   g sin   g cos g cos   g sin  f  mg cos   tan 50. Without friction the acceleration of the block would be… A) a  g sin  a  g sin   g cos g cos C) a  g sin  D) a  g E) a  tan B) F 51. A force F is exerted by a broom handle on the head of the broom, which has a mass m. The handle is at an angle θ to the horizontal, as shown above. The work done by the force on the head of the broom as it moves a distance d across a horizontal floor is A) Fd sin θ B) Fd cosθ C) Fm cos θ D) Fm tan θ E) Fmd sin θ θ 2 52. To stretch a certain nonlinear spring by an amount x requires a force F given by F = 40x - 6x , where F is in Newtons and x is in meters. What is the work done by the spring when the spring is stretched 2 meters from its equilibrium position? A) 16 J B) 28 J C) 56 J D) 64 J E) 80 J AP Physics 1st Semester Final Exam Review Page 13 53. When a block slides a certain distance down an incline, the work done by gravity is 300 J. What is the work done by gravity if this block slides the same distance up the incline? A) 300 J B) Zero C) -300 J A) It cannot be determined without knowing the distance the block slides. B) It cannot be determined without knowing the coefficient of friction. 54. An object of mass m is lifted at constant velocity a vertical distance H in time T. The power supplied by the lifting force is: A) mgHT B) mgH/T C) mg/HT D) mgT/H E) zero 55. A person pushes a box across a horizontal surface at a constant speed of 0.5 meter per second. The box has a mass of 40 kilograms, and the coefficient of sliding friction is 0.25. The power supplied to the box by the person is: A) 0.2 W B) 5 W C) 50 W D) 100 W E) 200 W 3/2 56. If a particle moves in such a way that its position x is described as a function of time t by x = t , then its kinetic energy is proportional to: 2 A) t 3/2 B) t C) t 1/2 D) t E) t° (i.e. kinetic energy is constant) 57. During a certain time interval, a constant force delivers an average power of 4 watts to an object. If the object has an average speed of 2 meters per second and the force acts in the direction of motion of the object, the magnitude of the force is: A) 16 N B) 8 N C) 6 N D) 4 N E) 2 N 58. Two identical massless springs are hung from a horizontal support. A block of mass 1.2 kilograms is suspended from the pair of springs, as shown above. When the block is in equilibrium, each spring is stretched an additional 0.15 meter. The force constant of each spring is most nearly: A) 40 N/m B) 48 N/m C) 60 N/m D) 80 N/m E) 96 N/m 1.2 kg AP Physics 1st Semester Final Exam Review Page 14 59. A rock is lifted for a certain time by a force F that is greater in magnitude than the rock's weight ‘mg’. The change in kinetic energy of the rock during this time is equal to the: A) Work done by the net force (F – mg). B) Work done by F alone. C) Work done by mg alone. D) Difference in the momentum of the rock before and after this time. E) Difference in the speed of the rock before and after this time. Questions 10 & 11: A spring has a force constant of 100 N/m and an un-stretched length of 0.07 m. One end is attached to a post that is free to rotate in the center of a smooth table, as shown in the top view at the right. The other end is attached to a 1 kg disc moving in uniform circular motion on the table, which stretches the spring by 0.03 m. Friction is negligible. Top View 60. What is the centripetal force on the disc? A) 0.3 N B) 3 N C) 10 N D) 300 N E) 1,000 N 61. What is the work done on the disc by the spring during one full circle? A) 0 J B) 94J C) 186 J D) 314J E) 628J 62. A specially designed spring is stretched from equilibrium to the distances x given in the table at the right and the restoring force F is measured and recorded in each case. What is the potential energy of the spring when it is stretched 3 m from equilibrium? A) 9/2 J B) 9 J C) 81/4 J D) 27 J E) 81/2 J 63. An ideal spring with spring constant k is cut in half. What is the spring constant of either one of the halves? A) k/2 1/2 B) k C) k 2 D) k E) 2k x(m) 0 1 2 3 4 F(N) 0 1 8 27 64 AP Physics 1st Semester Final Exam Review Page 15 Questions 14 & 15: Refer to the graph at the right which represents a hypothetical potential energy curve for a particle of mass m. 64. If the particle is released from rest at position r0, its speed at position 2r0 is most nearly A) 8U 0 m B) 6U 0 m C) 4U 0 m D) 2U 0 m E) 3U0 U0 x r0 U0 m 65. If the potential energy function is given by U(r) = br for the force on the particle? 3b 5 / 2 r (A) 2 3b 1 / 2 r (B) 2 3 1 / 2 r (C) 2 U(x) -3/2 2r0 + c, where b and c are constants, which of the following is an expression (D) 2br 1/ 2  cr 2b 5 / 2 (E) A r  cr 5 2 66. To stretch a certain nonlinear spring by an amount x requires a force F given by F = 40x - 6x , where F is in newtons and x is in meters. What is the change in potential energy when the spring is stretched 2 meters from its equilibrium position? (A) 16 J (B) 28 J (C) 56 J (D) 64 J (E) 80 J 67. A 10-kilogram body is constrained to move along the x-axis. The potential energy U of the body in joules is given as a function 2 of its position x in meters by the function U(x) = 6x - 4x + 3. At x = 3 m, the force on the particle is: (A) 32 N in +x direction (B) 32N in -x direction (C) 45 N in +x direction (D) 45 N in -x direction (E) 98 N in +x direction AP Physics 1st Semester Final Exam Review 68. A conservative force has the potential energy function U(x), shown by the graph at the right. A particle moving in one dimension under the influence of this force has kinetic energy 1.0 joule when it is at position x1. Which of the following is a correct statement about the motion of the particle? (A) It oscillates with maximum position x2 and minimum position x0. (B) It moves to the right of x3 and does not return. (C) It moves to the left of x0 and does not return. (D) It comes to rest at either x0 or x2. (E) It cannot reach either x0 or x2. Page 16 U(x) 1.0 J 0 x0 x x1 x2 x3 –1.0 J –2.0 J 69. When an object is moved from rest at point A to rest at point B in a gravitational field, the net work done by the field depends on the mass of the object and (A) the positions of A and B only (B) the path taken between A and B only (C) both the positions of A and B and the path taken between them (D) the velocity of the object as it moves between A and B (E) the nature of the external force moving the object from A to B In the system of two blocks and a spring shown above, blocks 1 and 2 are connected by a string that passes over a pulley. The initially un-stretched spring connects block 1 to a rigid wall. Block 1 is released from rest, slides to the right and is eventually brought to rest by the spring and by friction on the horizontal surface. k Block 1 Block 2 70. Which of the following is true of the energy of the system during this process? (A) The total mechanical energy of the system is conserved. (B) The total mechanical energy of the system increases. (C) The energy lost to friction is equal to the gain in the potential energy of the spring. (D) The potential energy lost by block 2 is less in magnitude than the potential energy gained by the spring. (E) The potential energy lost by block 2 is greater in magnitude than the potential energy gained by the spring. 71. After block 1 comes to rest, the force exerted on it by the spring must be equal in magnitude to (A) Zero. (B) The frictional force on block 1. (C) The vector sum of the forces on block 1 due to the friction and tension in the string. (D) The sum of the weights of the two blocks. (E) The difference in the weights of the two blocks. 2 72. When a certain non-ideal spring is stretched by an amount x, it produces a restoring force F(x) = -ax + bx where a and b are constants. How much work is done by an external force in stretching the spring by an amount D from its equilibrium length? 2 (A) –aD +bD (B) a – 2bD 2 3 (C) 0.5aD – 0.333bD 2 3 (D) –aD + bD 2 3 (E) –2aD + 3bD