Answer:
0.73 s
Step-by-step explanation:
The glass is in free fall, so its vertical position at time t is given by the equation:

where
h = 2.6 m is the initial height
u = 0 is the initial velocity of the glass
is the acceleration of gravity (downward since it is negative)
We want to know the time t at which the glass reaches the ground, so when
y(t) = 0
So the equation becomes

And solving for t, we find
