An object is thrown vertically upward with an initial speed and later returns to the…

PHYSICS · Subjective · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

An object is thrown vertically upward with an initial speed

u

and later returns to the same point of projection. When its vertical displacement is written as

s = ut + \tfrac12 (-g)t^2

, two positive values of

t

are obtained from the quadratic equation. In not more than two sentences, explain what these two values physically represent.