Assume you have a rigid body falling into the ocean at terminal velocity. Also assume that the rigid body does not break on impact. How could you figure out how much kinetic energy would be lost in the resulting splash? I promise this isn't a homework question, but an engineering thought experiment. I began to reason that water is incompressible so the body has to displace the water. I know the volume of my object so I could say I know how much water gets displaced. I also have a figure that the splash (radial jet) leaves at 20-30 times the impact speed. From there I can calculate a KE, but I don't believe it because this doesn't account for the surface tension. Any guidance would really be appreciated.
[Physics] Kinetic energy loss when a rigid body falls into water
collisionenergy-conservationfluid dynamics
Best Answer
The final velocity in the fluid is zero if there is no gravity so all kinetic energy is lost. If there is gravity, the body will move down with the velocity determined with balance of the gravity, Archimedes', and friction forces. It has nothing to do with the initial velocity.