Daily rise and fall of earth's waters on its coastline caused by gravitational interaction is called what?

• A. Tide
• B. Wave
• C. Current
• D. Gust

Answer: (A)

Tides are the daily rise and fall of sea level along coastlines caused by the gravitational pull of the Moon and the Sun on Earth's oceans. The Moon’s gravity pulls on the near side of Earth more strongly, creating a bulge, while inertia causes a bulge on the far side; as the planet rotates, coastlines move into and out of these bulges, producing high and low tides. The Sun also exerts gravity, strengthening or weakening tides depending on the alignment of the Sun, Moon, and Earth. When they line up, tides are higher (spring tides); when they’re at right angles, tides are lower (neap tides). Waves, currents, and gusts are different phenomena: waves are energy moving across the surface, currents are long-distance water movements, and gusts are sudden bursts of wind.