Question

An object is thrown vertically from a height of `3 m` at `3 m/s`. How long will it take for the object to hit the ground?

Answer 1

time = 1.6 sec

Explanation:

The object is thrown from a height 8m, when it reaches at ground its displacement h= - 8m, its initial upward velocity u = 3m/s
if acceleration due to gravity g is taken as -10 `ms^_2` then equation can be written as follows

`h =ut+1/2.g*t^2`
Or. -8 = 3t -0.5x10x`t^2`
Or `5t^2-3t-8 =0`
Or `(5t-8)(t+1) =0`
so feasible solution is t = 8/5 = 1.6 s