Question

what two measurements are necessary for calculating velocity? distance and time displacement and time

Explanation:

Velocity is a vector quantity. Its formula is $v = \frac{\Delta x}{\Delta t}$, where $\Delta x$ is displacement and $\Delta t$ is time. Displacement is a vector - it has magnitude and direction, while distance is a scalar. So displacement and time are needed for velocity calculation.

Answer:

Displacement and time