An object is attached to a vertical ideal massless spring and bobs up and down between the two extreme points A and B. When the kinetic energy of the object is a minimum, the object is located
A) at either A or B.
B) midway between A and B.
C) 1/3 of the distance from A to B.
D) 1/4 of the distance from A to B.
E) 1/ times the distance from A to B.

Question

An object is attached to a vertical ideal massless spring and bobs up and down between the two extreme points A and B. When the kinetic energy of the object is a minimum, the object is located
A) at either A or B. 
B) midway between A and B. 
C) 1/3 of the distance from A to B. 
D) 1/4 of the distance from A to B. 
E) 1/ times the distance from A to B.

Quizplus · Accepted Answer

At the extreme points A and B, the object comes to rest and all its energy is potential energy. At any point between A and B, the object will have some amount of kinetic energy along with potential energy. Therefore, the minimum kinetic energy will be at the points A and B where the object comes to rest, making option A the correct choice.

An Object Is Attached to a Vertical Ideal Massless Spring