Question

Which formula is used to calculate average velocity?

V Subscript a v g Baseline = StartFraction x Subscript f Baseline minus x Subscript I Baseline over t Subscript f Baseline minus t Subscript i Baseline EndFraction
V Subscript a v g Baseline = StartFraction t Subscript f Baseline minus t sub I over x sub f minus x sub I

v Subscript a v g Baseline = StartFraction t over d EndFraction

Answer 1

The first formula:

v_avg = (x_f − x_i) / (t_f − t_i).

This gives average velocity = displacement divided by elapsed time (vector quantity; sign gives direction). The other two are incorrect: the second has time and displacement swapped, and the third (t/d) is time over distance, not velocity.