Free ASVAB Practice Tests

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.

Smaller rocks shed by asteroids and comets are called meteoroids. When these rocks reach Earth's atmosphere, they burn up in the mesosphere and become meteors. If a meteor manages to reach the Earth, it is called a meteorite.

A concentrated load acts on a relatively small area of a structure, a static uniformly distributed load doesn't create specific stress points or vary with time, a dynamic load varies with time or affects a structure that experiences a high degree of movement, an impact load is sudden and for a relatively short duration and a non-uniformly distributed load creates different stresses at different locations on a structure.

The area of a triangle is equal to ½ base x height:

a = ½bh
a = ½ x 6 x 7 = \( \frac{42}{2} \) = 21

To convert a negative exponent to a positive exponent, calculate the positive exponent then take the reciprocal.

To balance this lever the torques at the green box and the blue arrow must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:

R_ad_a = R_bd_b

Solving for d_b, our missing value, and plugging in our variables yields:

d_b = \( \frac{R_ad_a}{R_b} \) = \( \frac{20 lbs. \times 1 ft.}{70 lbs.} \) = \( \frac{20 ft⋅lb}{70 lbs.} \) = 0.29 ft.

Calculate the number of vans needed by dividing the number of people that need transported by the capacity of one van:

vans = \( \frac{97}{8} \) = 12\(\frac{1}{8}\)

So, it will take 12 full vans and one partially full van to transport the entire team making a total of 13 vans.

An automobile's electrical system runs on DC power and the bulk of that power is supplied by the battery. The alternator converts the motion of the rotor into AC power which is then fed through the rectifier to convert it to DC power that both the car and the battery can use.