Free ASVAB Practice Tests

A compound is a substance containing two or more different chemical elements bound together by a chemical bond. In covalent compounds, electrons are shared between atoms. In ionic compounds, one atom borrows an electron from another atom resulting in two ions (electrically charged atoms) of opposite polarities that then become bonded electrostatically.

The volume of a cube is height x length x width:

v = h x l x w
v = 5 x 1 x 4
v = 20

The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:

x² + 6x - 13 = -x + 5
x² + 6x - 13 - 5 = -x
x² + 6x + x - 18 = 0
x² + 7x - 18 = 0

Next, factor the quadratic equation:

x² + 7x - 18 = 0
(x - 2)(x + 9) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (x - 2) or (x + 9) must equal zero:

If (x - 2) = 0, x must equal 2
If (x + 9) = 0, x must equal -9

So the solution is that x = 2 or -9

The yearly interest charged on this loan is the annual interest rate multiplied by the amount borrowed:

interest = annual interest rate x loan amount

i = (\( \frac{6}{100} \)) x $300
i = 0.06 x $300
i = $18

A nail is a short pin-shaped shaft of steel that's typically used to fasten pieces of wood together. It has a flat head on one end and a point on the other. A rivet consists of a cylindrical shaft with a head on one end and a tail on the other. When the rivet is installed, the tail is expanded and reshaped to form another head, creating a dumbell shape that will hold two surfaces together semi-permanently.

An inductor is coiled wire that stores electric energy in the form of magnetic energy and resists changes in the electric current flowing through it. If current is increasing, the inductor produces a voltage that slows the increase and, if current is decreasing, the magnetic energy in the coil opposes the decrease to keep the current flowing longer. In contrast to capacitors, inductors allow DC to pass easily but resist the flow of AC.

A block and tackle is a combination of one or more fixed pulleys and one or more movable pulleys where the fixed pulleys change the direction of the effort force and the movable pulleys multiply it. The mechanical advantage is equal to the number of times the effort force changes direction and can be increased by adding more pulley wheels to the system. An easy way to find the mechanical advantage of a block and tackle pulley system is to count the number of ropes that support the resistance.

After air enters through the nose, it passes through the nasal cavity which filters, moistens, and warms it. Further filtering takes place in the pharynx, which also helps protect against infection, and then in the trachea which is just past the epiglottis, responsible for preventing food from entering the airway.

In the mesosphere, temperature again drops as altitude increases until the coldest point in the Earth's atmosphere, the mesopause, is reached where temperatures fall to −225 °F (−143 °C).