Answer:
h=20.38 m
Step-by-step explanation:
Given that
Initial speed of object u = 20 m/s
Acceleration
![g= 9.8\ (m)/(s^2)](https://img.qammunity.org/2020/formulas/physics/high-school/96njwop7dlboyievf8ra9xpqifmb2mfgif.png)
We know that
![v^2=u^2-2gh](https://img.qammunity.org/2020/formulas/physics/high-school/rmey40y3f5glaoftpprnw1cdourxooo066.png)
Here acceleration and velocity is in opposite direction so the object will come rest after reaching at distance h.When body will reach at its highest position then velocity will become zero(v=0).
Now by putting the values
![v^2=u^2-2gh](https://img.qammunity.org/2020/formulas/physics/high-school/rmey40y3f5glaoftpprnw1cdourxooo066.png)
![0 =20^2-2* 9.1* h](https://img.qammunity.org/2020/formulas/physics/high-school/jb7wq6qlescc96ve1zjcvcu44nqmy5wmnc.png)
h=20.38 m