Physics Review Question
Unit: Circular Motion
Year: 1990 Question#: 63
Question: If the string is cut when the object is at the position shown,
the path the object will travel from this position will be
(1 ) Toward the center of the circle
(2 ) A curve away from the circle
(3 ) A straight line tangent to the circle
What is this question really asking?
Explanation by: Chris and Kate
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Answer 1
Toward the center of the circle
INCORRECT
Velocity is perpendicular to acceleration since it's traveling in a circle. You might be
confusiong velocity with acceleration which IS directed towards the center. return
to top
Answer 2
A curve away from the circle.
INCORRECT
The velocity vector will not change once the string is cut. The law of inertia dictates
objects naturally travel with a constant velocity. return to top
Answer 3
A straight line tangent to the circle.
CORRECT
Velocity is perpendicular to acceleration which is towards the center, therefore velocity
is a straight line tangent to the circle. return to top
return to top
What's this question really asking?
What is the object's instantaneous velocity? return to top
