I. Which of the following physical quantities is not a vector:
A. Force
B. Impulse
C. Angular velocity
D. Momentum
E. Energy
II. The gravitational attractive force between two objects is F, if they are separated by a distance of R. What will be the force if their separation is increased to 4R?
A. 0.25F
B. 0.0625F
C. 4F
D. 16F
E. Not enough information for an answer
III. A red ball traveling with a speed of v has an elastic head-on perfect elastic collision with a black ball initially at rest. Both balls have the same mass, and they are confined to move on a frictionless horizontal plane. Which of the following statements is not correct:
A. The total momentum remains the same before and after the collision.
B. The total kinetic energy remains the same before and after the collision.
C. The center of mass of the two balls always move with a constant velocity, the collision has no effect on its motion.
D. The balls will stick and move together as one piece.
E. The collision is absolute quiet and will not generate any heat.
IV. A roller coaster is released from rest at point O as shown in the diagram. The track is frictionless and assume the roller coaster stays on the track for the whole trip. At which point the roller coaster will move fastest?
A. Point P
B. Point Q
C. Point R
D. Point S
E. Point T
V.
An object is hung at point O. A plumb line is also attached to the same point as shown in the diagram. Which of the following statements is not correct:
A. The center of mass of the object has to be on the vertical line OA.
B. If the object is released, its center of mass will accelerate downward with an acceleration of 9.8 m/s2.
C. If the object is divided into N small pieces, each has a mass of
mi and a height of yi above ground level (y=0). The
position of the center of mass above ground level is given by
D. The center of mass has to be inside the body of the object.
E. If an extra mass is attached to the original object at point B, the center of mass will move closer to B.