Solve Free Fall Problem: Object Launched at 25 m/s, Reaches 20m at 2.55 s

[cheerspens]

Homework Statement

An object is launched upwards with a velocity of 25 m/s. At what time (or times) will the object be located twenty meters above the ground?

Homework Equations

The Attempt at a Solution

I started off with the following variable list:
Xo=0 Vo=25
X=0 V=0
t=? a=-9.8
Which seems very off to me.
When trying to solve I got 2.55 seconds. But is there another time where it reaches 20m?
How do you solve this?
Thanks!

 

[rock.freak667]

The Attempt at a Solution

I started off with the following variable list:
Xo=0 Vo=25
X=0 V=0
t=? a=-9.8
Which seems very off to me.
When trying to solve I got 2.55 seconds. But is there another time where it reaches 20m?
How do you solve this?
Thanks!

x=V_0 t-\frac{1}{2}gt^2


will help you. Remember it is going up, reaching maximum height and falling back down to the ground. So at two times it will be 20m up in the air.

 

[cheerspens]

Would my answers be 0.994sec and 1.557sec?