Elastic potential energy.
When you stretch a rubber band it has the "potential" to do work, to fly in a given direction. In doing so it changes it's elastic potential energy to kinetic energy.
Sonar<span> (originally an acronym for Sound Navigation And Ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels.</span>
Directly proportional to pressure
Kinetic Energy is defined by Ke=1/2mv^2. Plug in and solve for v.
2,000 = 1/2(1000)(v)^2
4=(v)^2
v=2 m/s
The car must move at 2 m/s to have a Ke of 2,000 Joules.