What is the kinetic energy that the device contains immediately before it hits the ground? [KE = / 2*m*v-]

Kinetic energy : "It is the energy possessed by body by virtue of its motion".

Explanation:

The mechanical energy is the energy that a body has due to its motion or position.

It is of two types:

Potential energy Kinetic energy

Potential energy

"It is the energy that a body has due to its position or state".

It is given by P. E=mgh

Kinetic energy

"It is the energy that a body has due to its motion".

The formula is : K. E=1/2mv².

For example

A ball is placed on table. At that time it has potential energy. Now, lets say that we push it and it drops down. On doing this, the potential energy of ball gets converted into kinetic energy (because it comes in motion) and as soon as it touches the ground it stops and its kinetic energy gets converted into Potential energy again.