Chapter three checked the ramp (triangle-area) work rule at a single displacement; this scan holds force fixed and scans displacement across three rows the way chapter five did for the constant-force rectangle rule. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Four metres under a ramping force gives half the rectangle area
Chapter three checked the ramp force-work rule once, at a single displacement. Here force stays 8 newtons while displacement varies: at 4 metres, the triangular area gives work 16 joules.
21⋅8⋅4=16
Six metres reproduces chapter three's own checked ramp case
The same force 8 newtons at displacement 6 metres gives work 24 joules, exactly chapter three's ramp-force-work-area example.
21⋅8⋅6=24
Eight metres doubles the triangular work from the first row
At displacement 8 metres, the same force gives work 32 joules. Three rows show the ramp rule scales linearly with distance, the same as chapter five's rectangle scan, but at half the constant-force value.