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The Cambrian period is one of the most significant geological time periods. Lasting about 53 million years, it marked a dramatic burst of changes in life on Earth known as the Cambrian Explosion. It is from this period that the majority of the history of life on Earth, as documented by fossils, is found. Called the fossil record, the layering of these mineralized imprints of organisms preserved in sedementary rock have allowed geologists to build a historical record of plant and animal life on Earth.

The equation for this sequence is:

a_n = a_n-1 + 6

where n is the term's order in the sequence, a_n is the value of the term, and a_n-1 is the value of the term before a_n. This makes the next number:

a₆ = a₅ + 6
a₆ = 25 + 6
a₆ = 31

An overcooled engine is less efficient. During the power stroke, combustion heat pushes down the piston. If too much of this heat is lost to the cooling system, the fuel might not combust completely and contaminate the engine's lubricating oil diminishing its lubricating ability. Incomplete combustion of fuel also negatively affects the engine's fuel efficiency and power output.

Gravitational potential energy is energy by virtue of gravity. The higher an object is raised above a surface the greater the distance it must fall to reach that surface and the more velocity it will build as it falls. For gravitational potential energy, PE = mgh where m is mass (kilograms), h is height (meters), and g is acceleration due to gravity which is a constant (9.8 m/s²).

Direct current flows in only one direction in a circuit, from the negative terminal of the voltage source to the positive. A common source of direct current (DC) is a battery.

According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:

c² = a² + b²
c² = 8² + 4²
c² = 64 + 16
c² = 80
c = \( \sqrt{80} \)

Wood chisels are used to shape or smooth wood surfaces. They come in a variety of widths and can be used with hand power or tapped with a mallet when deeper cuts need to be made.

The primary component of the lubrication system is engine oil. Engines require oil blends with different thickness (viscosity) and additives depending on their operating conditions. Viscosity is rated using the format XW-XX with the number preceding the W (winter) rating the oil’s viscosity at 0 ℉ (-17.8 ℃) and the XX indicating viscosity at 100 ℃.

The oil pan contains the engine oil reservoir of from four to six quarts of oil and feeds the oil pump through the oil pickup tube. An oil strainer floats at the top of the oil in the oil pan and screens debris from the oil before feeding it to the oil pump.

Inline cylinder arrangements number cylinders sequentially (1, 2, 3, ...) front to rear.