How do you work this

This is just a freely falling bodies problem, the only difference is that rater than

g = 9.8 m/s^2 we have g = 1.62 m/s^2

The relevant equation is

Where g is -1.62 m/s^2, t is time in seconds, y is -1.25 m, yo is zero and vo is zero (initial velocity and position are both zero). We need to solvefor t first.

-1.25 = (-1.62)t^2 + 0 + 0

t = sqrt (-1.25/-1.62) = .878 seconds

Now that we know how long the rock took to hit the ground, we use the equation

v = -1.62*(.878) + 0

v = -1.42 m/s

I assume you want a positive answer, since gravity was given as a positive value, so your answer is

v = 1.42 m/s

Hope that helps, good luck!