Mini-Quiz: Relative Motion and Center of Mass

1. If you see two objects in space moving in the same direction and parallel to each, how is the CM between them moving? The CM is stationary, since the objects are moving together The CM rotates on its axis It is moving along with them in the same direction 2. If an object is moving toward the stationary CM, how does the other object mirror the motion?

   The CM is stationary, since the objects are moving togetherGood try, but not right. Select another answer.The CM rotates on its axisSorry, not correct. Try another button.It is moving along with them in the same directionOops! Wrong answer. Re-read the question and try again.It moves away from the CM at the same speedThat is correct.It also moves toward the CM but in the opposite directionGood try, but not right. Select another answer.It depends on how fast the CM is movingSorry, not correct. Try another button.

2. Why would you view the motion of one object with respect to the other?

   It may be a more convenient perspectiveCorrect. You know about relative motion. You would never view one object with respect to the otherGood try, but not right. Select another answer. You always do this when on the EarthOops! Wrong answer. Re-read the question and try again.

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