Ch. 5: Gravity

What are the fundamental forces in nature?

gravity, electromagnetic forces, and the strong and weak nuclear forces.

nuclear forces

operate within the nucleus of an atom holding it together.

electromagnetic forces

operate within and between atoms holding molecules together.

gravity

an object pulls on another object.

weight

the force exerted by gravity on an object, dependent on its mass and the acceleration due to gravity.

universal law of gravity

states that every point mass attracts every other point mass with a force proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

inverse square law

a physical law stating that the strength of a force decreases with the square of the distance from the source.

spring tides

the twice-monthly high tides that occur when the Earth, moon, and sun are aligned, leading to higher than usual tidal ranges.

neap tides

the tides that occur when the Earth, moon, and sun form a right angle, resulting in lower than normal tidal ranges.