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?

1 Answer
Apr 25, 2016

Answer:

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#