Question

An object is thrown vertically from a height of `2 m` at `3 m/s`. How long will it take for the object to hit the ground?

Answer 1

I found `1.01s`

Explanation:

I would try using the general kinematic relationship:
`y_f-y_i=v_it+1/2at^2`
where:
`y_i` is the initial position;
`y_f` is the final position (the ground);
`v_i` is the initial velocity;
`a` is the acceleration of gravity (directed downwards):
so you should get:
`0-2=3t-1/2*9.8t^2`
`4.9t^2-3t-2=0`
solving the Quadratic Equation gives us:
`t_1,2=(3+-sqrt(9+39.2))/9.8=`
two solutions:
`t_1=1.01s`
`t_2=-0.4s`