<span>D. density is your answer</span>
Explanation:
Hydraulic systems use the pump to push hydraulic fluid through the system to create fluid power. The fluid passes through the valves and flows to the cylinder where the hydraulic energy converts back into mechanical energy. The valves help to direct the flow of the liquid and relieve pressure when needed
I don't like the wording of any of the choices on the list.
SONAR generates a short pulse of sound, like a 'peep' or a 'ping',
focused in one direction. If there's a solid object in that direction,
then some of the sound that hits it gets reflected back, toward the
source. The source listens to hear if any of the sound that it sent
out returns to it. If it hears its own 'ping' come back, it measures
the time it took for the sound to go out and come back. That tells
the SONAR equipment that there IS a solid object in that direction,
and also HOW FAR away it is.
RADAR works exactly the same way, except RADAR uses radio waves.
There are
different kinds of forces; applied force, force of gravity, friction force,
normal force, tension force. We will focus on the common forces, applied force
and force of gravity. An applied force is a force that is applied to an object
by another object. The force of gravity is the force with which massively large
objects such as the earth attracts another object towards itself. All objects
of the earth exert a gravity that is directed towards the center of the earth.
Therefore, the force of gravity of the earth is equal to the weight of the
object.
