12. A rubber band ball of mass m is attached to a string of length R as shown above. The ball is released from rest from position X where the string is horizontal, swings through position Y where the string is vertical, and reaches position Z where the string is again horizontal. What are the directions of the acceleration vectors of the ball at positions Y and Z? Position Y Position Z (A) Downward Downward (B) Downward To the right (C) Upward Downward (D) Upward To the left (E) To the right To the left 13. As above, two blocks are pushed along a horizontal frictionless surface by a 30 newton force to the right. The force that the 4kilogram block exerts on the 6kilogram block is (A) 8 newtons to the left (B) 8 newtons to the (C) 10 newtons to the left (D) 12 newtons to the left (E) 12 newtons to the right 14. A mass m 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?
12. A rubber band ball of mass m is attached to a string of length R as shown above. The ball is released from rest from position X where the string is horizontal, swings through position Y where the string is vertical, and reaches position Z where the string is again horizontal. What are the directions of the acceleration vectors of the ball at positions Y and Z? Position Y Position Z (A) Downward Downward (B) Downward To the right (C) Upward Downward (D) Upward To the left (E) To the right To the left 13. As above, two blocks are pushed along a horizontal frictionless surface by a 30 newton force to the right. The force that the 4kilogram block exerts on the 6kilogram block is (A) 8 newtons to the left (B) 8 newtons to the (C) 10 newtons to the left (D) 12 newtons to the left (E) 12 newtons to the right 14. A mass m 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?
Dynamics_Multiple_Choice-2012-02-13.docx