A ball is projected vertically upwards its speed at half of maximum height is 20 m/s what is the maximum height attained by it

Q. A stone is thrown vertically upwards. When stone is at a height half of its maximum height, its speed is $10m/s;$ then the maximum height attained by the stone is (g= $10m/s^2$)

Q. A particle is thrown vertically upwards. Its velocity at half of the maximum height is $20\text{m/s}$. Then the maximum height attained by it will be: (Take $g=10{\text{m/s}}^2$)

Q. If an object projected vertically upwards with speed$,$ half the escape speed of earth$,$ the maximum height attained by it is $($R is radius of the earth$)?$

Q. If an object is projected vertically upwards with speed,half the escape speed of earth, then the maximum height attained by it is [R is radius of earth]