Energy of the Sea

Newton's law of universal gravitation states that any two bodies in the universe attract each other with a force that is proportional with their masses and inversely proportional to the square of the distance between them. (Wikipedia Newton’s law of universal gravitation)

Every point mass attracts every single other point mass by a force pointing along the line intersecting both points. The force is proportional to the product of the the two masses and inversely proportional to the square of the distance between them. (Wikipedia Newton’s law of universal gravitation)

·        F is the force between the masses, measured in newtons (N)

·        G is the gravitational constant, equals to .6.74 * 10^-11 (N*m² * kg^-2)

·        m₁ is the first mass, in kilograms (kg)

·        m₂ is the second mass, in kilograms (kg)

·        r is the distance between the centers of the masses, in meters (m)

Gravitational attraction is inversely proportional to the square of the distance between two masses.

The tide generating force is inversely proportional to the cube of the distance between each point on Earth and the center of the tide-generating body (Sun or Moon).

Tide-generating forces are small averaging about one-millionth the magnitude of Earth’s gravity. However, their maximum value at points on Earth’s surface at “latitude” of 45 degrees relative to the “equator” between the zenith and nadir.

Using tide power as source of energy:

There have been people in the history use ocean tides as a source of power. In the 12^th century, water wheels driven by the tides were used to power gristmills and sawmills. During the 17^th and 18^th centuries much of Boston’s flour was produced at a tidal mill.

Tide power is considered to be a clean, renewable source of energy with vast potential of generating electricity. Tides are more predictable than wind and solar energy. Like other kinds of renewable energy, it suffers from high cost and limited availability of sites. Even though the initial cost of building the plant is relativity higher than traditional thermal power plant, but the operating cost would less because it does not use fossil fuels or radioactive substances to generate electricity. (From our text book, pg 296)