An open elevator is ascending with zero acceleration and speed $10m/s.$ A ball is thrown vertically up by a boy (boy is in elevator) when he is at a height $10m$ from the ground, the velocity of projection is $30m/s$ with respect to elevator. Choose correct option(s) assuming height of the boy very small:$\left(g=10m/s^2\right)$

Q. An elevator without a ceiling is ascending with a constant speed of $10m/s$. A boy on the elevator shoots a ball directly upward, from a height of $2.0m$ above te elevator floor. At this time the elevator floor is $28m$ above the ground. The initial speed of the ball with respect to the elevator is $20m/s$. (g= $10m/s^2$). What maximum height above the ground does the ball reach?

Q. An elevator without a ceiling is ascending up with an acceleration of $5{\text{ms}}^{-2}$. A boy on the elevator shoots a ball in vertical upward direction from a height of $2\text{m}$ above the floor of elevator. At this instant the elevator is moving up with a velocity of $10{\text{ms}}^{-1}$, and the floor of the elevator is at a height of $50\text{m}$ from the ground. The initial speed of the ball is $15{\text{ms}}^{-1}$ with respect to the elevator. Consider the duration for which the ball strikes the floor of elevator in answering following questions. ($g=10{\text{ms}}^{-2}$)

Q. A very broad elevator is going up vertically with a constant acceleration of $2m/s^2$. At the instant when its velocity is $4m/s$ a ball is projected from the floor of the lift with a speed of $4m/s$, relative to the floor at an elevation of ${30}^o$. The time taken by the ball to return the floor is
($g=10m/s^2$)

Q. From the top of the tower of height $40m$, a ball is projected upwards with a speed of $20m/s$ at an the angle of elevation of ${30}^{\circ }$, The ratio of the total time taken by the ball to hit the ground to fits time of flight (time is taken to come back to the same elevation) is (take $g=10m/s^2)$