Answer
(a) Displacement greater for stone thrown horizontally.
(b) Impact speed greater for stone thrown horizontally.
(c) Time of flight same for both stones.
Work Step by Step
Since both of them have the same initial vertical velocity and same vertical acceleration, the time taken by both of them is equal to reach the ground. Hence the time of flight is the same in both the cases.
The change in potential energy from the top to the bottom goes into the kinetic energy, so the change in energies for both of them is equal because the change in height is the same. Since the first particle has higher initial kinetic energy, it has greater final kinetic energy, and therefore the greater final speed.
Since the vertical displacement is same for the both but the first one has a horizontal displacement too, it has a greater net displacement.
