The work done by the block on the spring and by the spring on the block is 7.22 J.
The given parameters;
Based on law of conservation of energy, the potential energy of the block will be converted to elastic energy of the spring, producing the given extension.
The work done by the block on the spring will be equal to work done on the block by the spring.
[tex]W = \frac{1}{2} kx^2\\\\W = \frac{1}{2} \times 400 \times 0.19^2\\\\ W = 7.22 \ J[/tex]
Thus, the work done by the block on the spring and by the spring on the block is 7.22 J.
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