The 2-kg collar is attached to a spring that has an un-stretched length of 3.0 m. If the collar is drawn to point B and releases from rest, what is the speed when it arrives at point A. Note that k = 3.0 N/m and neglect friction.

Complete Question

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Explanation:

From the question we are told that

   The mass of the collar is  

    The original length is  

     The spring constant is  

Generally the extension of the spring  is  mathematically evaluated as

Now with Pythagoras theorem we can obtain the length from A to B as

The  extension of the spring at B is  

According to the law of energy conservation

   The energy stored in the spring at point A +  the kinetic energy of the  spring =  The  energy stored on the spring at B

So

substituting values

=>  

i think it's 35 meters