Introduction to SAT II Physics

more light elements—often hydrogen—together to form a heavier element. As with
fission, this fusion releases a tremendous amount of energy.
Fusion reactions can only occur under intense heat. Humans have only been able to
produce a fusion reaction in the hydrogen bomb, or H-bomb, by first detonating an
atomic bomb whose fission produced heat sufficient to trigger the fusion reaction.
Scientists hope one day to produce a controllable fusion reaction, since the abundance of
hydrogen found in this planet’s water supply would make nuclear fusion a very cheap and
nonpolluting source of energy.

Key Formulas

Time

Dilation

Length

Contraction

Addition of

Relativistic

Velocities

Relativistic

Mass

Relativistic

Kinetic

Energy

Mass-Energy

Equivalence

Electron-

Volts Related

to Joules

Energy as a

function of

frequency

Kinetic

Energy of

Liberated