Here as we know that there is no loss of energy
so we can say that maximum kinetic energy will become gravitational potential energy at its maximum height
So here we have
![(1)/(2)mv^2 = mgh](https://img.qammunity.org/2020/formulas/physics/high-school/dlz24jomhu7oiwhvg025hgfsvx8jzb99zg.png)
here we have
v = 20 m/s
m = 8000 kg
now from above equation we have
![(1)/(2)(8000)(20^2) = (8000)(9.8)h](https://img.qammunity.org/2020/formulas/physics/high-school/sxr1fbbukb9cjs90skcuw4iehdkf5d82kp.png)
![h = \frac{200}{9.8)]()
![h = 20.4 m](https://img.qammunity.org/2020/formulas/physics/high-school/mk84aqy08dt9wkqfn26g92j5vl0qrtcrpt.png)
so maximum height is 20.4 m