text: horitzontal projectile motion.? a ball is rolled off of a building that is 5m tall. will the ball go over a wall that is 20m away and 2m tall? or will it hit the wall? basically the question is how far from the ground will the ball be after traveling 20m.  v= 31.25 m/s  show all work please. traveling at 31.25 m/s, the ball would reach 20 m in .64 seconds.  according to galileo's free-fall, objects have a 9.81 acceleration.  so, in .64 seconds, the ball would have fallen 2.00704 m.  subtract that from 5 m, you would get a number greater than 2 m, so i assume that if would clear the wall. i think.  (to above) isn't time equal to distance divided by velocity? for example, it travels at 31.25 m/s, so it would travel 31.25 meter in one second. doesn't that go to say that 20 meter would take less than a second?