Three constant-velocity rows hold speed fixed while time changes, so distance can be read as a growing ledger.
Example
Holding velocity fixed while time changes makes distance grow row by row. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
Hold velocity fixed and scan time
A constant velocity row is a distance ledger. The speed stays 3 m/s, and each larger time extends the travel distance by the same amount again.
x=vt
Short time
After 2 s, the cart covers 6 m.
x=vt=3m/s⋅2s=6m
Middle time
After 4 s, the same velocity covers 12 m.
x=vt=3m/s⋅4s=12m
Long time
After 6 s, the distance reaches 18 m.
x=vt=3m/s⋅6s=18m
The distance column grows with time
The velocity column is unchanged. The time column changes, so the distance column changes in the same ratio.
v3m/s3m/s3m/st2s4s6sx6m12m18m
mechanicsAt 3 m/s, the times 2 s, 4 s, and 6 s give distances 6 m, 12 m, and 18 m.