Waterfall physics problem-Help me get to answer!

Question

Consider a waterfall with the river water flowing horizontally off of a cliff at 2.1 m/s before falling 120 m to a lake below. After leaving the cliff it takes the water 4.9 seconds to fall to the lake. Later on, following a heavy rainstorm, the river flows faster causing the water to flow horizontally off of the cliff a 4.2 m/s. How long does it take the water to fall to the lake in this case?

Answer: 4.9 s

Answer 1

The falling time is 4.9 sec in both cases because the downward force of gravity is still the same. The difference is in Where the water stream hits the lake. Moving faster after the rainstorm, the water shoots farther out. That is, the horizontal vector is greater while the vertical vector is the same. The path is a little longer, but the water is moving faster so that the transit time is the same.

Every rifle or artillery man knows this "rule"............. ;-)