What is the apparent deflection of a moving object from its initial course due to Earth's rotation, deflecting to the right in the Northern Hemisphere and to the left in the Southern Hemisphere?

• A. Gravity
• B. Coriolis Effect
• C. Centrifugal Force
• D. Magnetic Force

Answer: (B)

The apparent deflection described is due to the Coriolis effect. On a rotating planet, moving objects don’t travel straight relative to the surface because the ground itself is rotating underneath. In the Northern Hemisphere this sideways deflection bends paths to the right, while in the Southern Hemisphere it bends them to the left. This happens because different latitudes have different tangential (east-west) speeds, and as objects move, conservation of angular momentum causes a sideways pull perpendicular to their motion. The strength of the effect grows with faster motion and with distance from the equator (zero at the equator, larger toward the poles). Gravity is a vertical force pulling toward the center of Earth, centrifugal force is a perceived outward push in a rotating frame, and magnetic force is unrelated to this motion.