💪 A steady net force does work — and the work becomes kinetic energy

A constant net force F pushes a block along a frictionless track. The work W = F·d piles up and, at every instant, equals the kinetic energy K. That is the work–energy theorem.
Step 1 — the block starts at rest.
F = 8 N · d = 0 m
W = 0 J · K = 0 J
v = 0 m/s · a = 0 m/s²
W = F·d · W = ΔK
start at rest → W = K