A2L Item 133
- Description: Recognize the direction of the acceleration of a ball on curved vertical track.
- Goal: Reasoning with circular motion
- Source: UMPERG-ctqpe37
- Keywords: Acceleration, Mechanics, Reasoning
The question for students:
A small ball is released from rest at position A and rolls down a vertical circular track under the influence of gravity.
When
the ball reaches position B, which of the indicated directions most
nearly corresponds to the direction of the ball’s acceleration?
Enter (9) if the direction cannot be determined.
Commentary for teachers:
Answer
(2) At position B the acceleration has a tangential component and a radial component. Both components can be determined at position B. Worked out carefully one gets 18 degrees above position #2. It is common for students to neglect one component or the other.