Halliday, Resnick & Walker — Force and Motion–I: Problem 78

Noninertial frame projectile. A device shoots a small ball horizontally with speed \(0.200 \text{ m/s}\) from height \(h = 0.800 \text{ m}\) above an elevator floor. The ball lands at distance \(d\) from the base of the device directly below the ejection point. The vertical acceleration of the elevator can be controlled. What is the elevator’s acceleration magnitude \(a\) if \(d\) is (a) \(14.0 \text{ cm}\), (b) \(20.0 \text{ cm}\), and (c) \(7.50 \text{ cm}\)?