Which term describes the deflection of moving objects caused by Earth's rotation, with no effect at the equator?

Which term describes the deflection of moving objects caused by Earth's rotation, with no effect at the equator?

• A. Coriolis Effect
• B. Gravity
• C. Pressure Gradient Force
• D. Friction

Answer: (A)

The main idea here is the Coriolis Effect—the sideways deflection that moving objects experience because Earth is rotating. This effect makes air and water drift to one side of their path rather than moving in a straight line relative to the ground. The key detail is that this deflection depends on latitude: at the equator there is no horizontal deflection, so moving objects travel straight across the surface as far as the rotation-induced sideways force is concerned. In the Northern Hemisphere they bend to the right, and in the Southern Hemisphere to the left, which helps shape large-scale wind and current patterns. Gravity pulls everything downward toward the center of the Earth, so it isn’t responsible for sideways deflection. The pressure gradient force drives flow from high to low pressure but doesn’t itself cause rotation-related deflection. Friction slows motion near the surface and can affect speed, but it’s not the cause of the sideways bend produced by Earth's rotation.

The main idea here is the Coriolis Effect—the sideways deflection that moving objects experience because Earth is rotating. This effect makes air and water drift to one side of their path rather than moving in a straight line relative to the ground. The key detail is that this deflection depends on latitude: at the equator there is no horizontal deflection, so moving objects travel straight across the surface as far as the rotation-induced sideways force is concerned. In the Northern Hemisphere they bend to the right, and in the Southern Hemisphere to the left, which helps shape large-scale wind and current patterns.

Gravity pulls everything downward toward the center of the Earth, so it isn’t responsible for sideways deflection. The pressure gradient force drives flow from high to low pressure but doesn’t itself cause rotation-related deflection. Friction slows motion near the surface and can affect speed, but it’s not the cause of the sideways bend produced by Earth's rotation.