Part C: Multiple Choice [_/8] 1. (A) An elevator, suspended by a cable, is moving upward at constant speed. The correct relationship between the magnitude of force of gravity on the elevator and tension force in the cable is: (A) the magnitude of force of gravity equals the magnitude of tension force (B) the magnitude of force of gravity is greater than the magnitude of tension force (C) the magnitude of force of gravity is less than the magnitude of tension force (D) the magnitude of force of gravity is less than or equal to the magnitude of tension force (E the magnitude of force of gravity is equal to or greater than the magnitude of tension force 2 . (K) A net force of 16 N [40 W of N] is caused by two applied forces acting on the same object. These two forces are: (A) 10 N [W] and 12 N [N] (B) 12 N [W] and 10 N [N] (C) 14 N [W] and 12 N [N] (D) 12 N [W] and 14 N [N] (F) 10 N [W] and 14 N [N] pg. 2 3. (A) A rope is hung over a pulley. Two masses are hung on opposite ends of the pulley. If mass X is greater than mass Y, then A) the force of tension on X is greater than the force of tension on Y (B) the force of tension on X is less than the force of tension on Y (C) the force of tension on X is equal to or greater than the force of tension on Y (D) the force of tension on X is less than or equal to the force of tension on Y (E) the force of tension on X equals the force of tension on Y (K) A shoe sits on a ramp without moving. As the angle of the ramp is increased, the shoe starts to move. This is because: (A) the normal force has increased (B) the coefficient of static friction has decreased (C) force of gravity on the shoe has increased (D) the component of the normal force along the ramp has increased (E) the component of gravity acting along the plane of the ramp has increased For Questions 5 - 8, use the following diagram. up West East down 5 . (K) A ball is attached to a string and whirled clockwise in a vertical circle. The direction of acceleration at the location indicated is: (A) down (B) up (C) East (D) West ( E) none of the above 6. (K) A ball is attached to a string and whirled clockwise in a vertical circle. The direction of instantaneous velocity at the location indicated is: (A) down (B) up (C) East (D) Ves (F) none of the above pg. 3 7. (K) A ball is attached to a string and whirled clockwise in a vertical circle. The direction of centripetal force at the location indicated is: (A) down (B) up (C) Eas (D) Wes (E) none of the above 8. (K) A ball is attached to a string and whirled clockwise in a vertical circle. The tension in the string will be the least: (A) at the bottom of the circle (B) at the top of the circle (C ) as the ball is moving toward the top of the circle (D) as the ball is moving toward the bottom of the circle (E) Nowhere. Tension will be the same at all points in the circle