A 2.5 kg block is launched along the ground by a spring with a spring constant of 56 N/m. The spring is initially compressed 0.75 m.

Assuming the spring’s stored energy becomes the block’s kinetic energy, set ½kx² = ½mv². Solving gives v = x√(k/m) = 0.75√(56/2.5) ≈ 3.55 m/s. This rounds to 3.5 m/s, choice A.

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