Final answer:
The Coriolis force is a fictitious force that causes apparent deflection of moving objects when viewed from a rotating frame of reference, such as the Earth's rotation. It is an integral concept in understanding the behavior of large-scale phenomena like weather systems and ocean currents.
Step-by-step explanation:
The deflection caused by a rotating object is known as the Coriolis force. This is a fictitious force or inertial force that occurs in a rotating frame of reference, such as Earth's rotation. The Coriolis force causes the apparent deflection of moving objects; for instance, if you slide a ball away from the center of a merry-go-round, the ball will follow a curved path relative to the rotating platform. This is because, while the ball moves in a straight line relative to the inertial frame of Earth, the rotating platform moves underneath it, resulting in an apparent deflection to the right (in the Northern Hemisphere) or left (in the Southern Hemisphere).
On a larger scale, the Earth is nearly an inertial frame and we ordinarily have to perform precise experiments to observe these fictitious forces. However, they become more noticeable in phenomena such as the rotation of weather systems and ocean currents. A key point about fictitious forces like the Coriolis force is that they do not have a physical origin like real forces (e.g., gravitational pull). They merely arise from observing motion from a noninertial, or accelerating, frame of reference. This allows the application of Newton's Laws in frames that are not inertial.