An object is thrown vertically from a height of #9 m# at # 5 m/s#. How long will it take for the object to hit the ground?

1 Answer
Mar 11, 2018

Let's construct an equation for the motion of the object.

Well here we will be using, #S=ut + 1/2 at^2#

Considering upward direction to be positive, we get, #S=-9# as on reaching the ground it will have a net displacement of #9m# downwards.

#u=5ms^-1# and #g=-9.8ms^-2#

So,if it takes time #t# to reach the ground we can write,

#-9 = 5t -1/2 ×9.8×t^2#

Solving this we get, #t=1.96s#