Answer:
Step-by-step explanation:
Impossible to say without knowing how high point D is.
If we ignore friction, the energy converted from potential energy will exist as kinetic energy.
let d be the height in meters of point D "in the air"
mg(19 - d) = ½mv²
m is common so divides out
g(19 - d) = ½v²
v = √(2g(19 - d))
no sense in making g any more precise than the height. g = 9.8
v = √(2(9.8)(19 - d))
v = √(19.6(19 - d))