Someone throws a set of keys vertically upward to a person in a window 4.20m above. Keys caught 1.75s later.?

Question

Part 1 - With what initial velocity were the keys thrown?
Part 2 - What was the velocity of the keys just before they were caught? (Take upward as the positive direction.)

Answer 1

h = v(i)t - (1/2)gt^2
v(i) = (h + (1/2)gt^2)/t
v(f) = v(i) - gt
v(i) = (4.2 + (1/2)(9.8)(1.75)^2)/1.75 = 19.5 m/s
v(f) = 19.50625 - 9.8*1.75 = 2.36 m/s