University of Akron October 12, 2009 Physics 261: Personal Response System Questions (A) What is ¾ of a full rotation, in terms of radians? 3 3 3 3 1. 270 rad 2. rad 3. rad 4. rad 5. rad 4 2 4 2 (B) A ladybug sits at the outer edge of a rotating merry-go-round, and a gentleman bug sits halfway between her and the axis of rotation. The gentleman bug’s angular speed is 1. half the ladybug’s. 2. the same as the ladybug’s. 3. twice the ladybug’s. 4. impossible to determine with information given. (C) Same situation as above, but compare linear speed. The gentleman bug’s linear speed is …? (D) As viewed from above, a turntable is observed to rotate counterclockwise. The angular velocity vector is 1. tangential to the rim of the turntable. 2. out of the plane of the turntable. 3. into the plane of the turntable. 4. in the counterclockwise direction. (E) If an object undergoes uniform circular motion (moves in a circle with a constant speed) 1. the net force on the object is zero. 2. the net force on the object is non-zero, and points in the direction of the velocity vector . 3. the net force on the object is non-zero, and points towards the center of the circle. 4. the net force on the object is non-zero, and points in the direction of the angular velocity vector.