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    Question

    A block of mass 2kg is pushed against a light spring of

    spring constant 200N/m and compressed by 0.2m on a horizontal surface with kinetic friction coefficient μk​ =0.1. When the spring is released, what is the maximum speed attained by the block?
    A 1.6 m/s Correct Answer Incorrect Answer
    B 1.0 m/s Correct Answer Incorrect Answer
    C 1.9 m/s Correct Answer Incorrect Answer
    D 1.2 m/s Correct Answer Incorrect Answer

    Solution

    We are given:

    • Mass of block: m = 2 kg
    • Spring constant: k = 200 N/m
    • Compression: x = 0.2 m
    • Coefficient of kinetic friction: μk = 0.1
    • Surface: horizontal (so normal force = mg)
    • Objective: Find the maximum speed attained by the block as the spring releases.
    When the compressed spring is released, it does work on the block, but some energy is lost to kinetic friction while the block is in contact with the spring. The maximum speed is attained just as the spring reaches its natural length , i.e., when all spring energy is transferred to the block (minus losses due to friction). Initial energy stored in spring

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