Free ASVAB Practice Tests

Brakes utlize friction to slow vehicle tires. Drum brakes employ a cast iron drum that roates with the vehicle axle. When hydraulic pressure is applied to the brake assemblies at the wheels, internal pistons expand and push brake shoes outward into contact with the brake drum slowing the rotation of the axle. More powerful disc brakes operate by pinching a rotating disc betweeen two brake pads and allow for a larger surface area to contact the disc, provide more force, and are more easily cooled.

The purpose of an automobile engine's cooling system is to circulate coolant around the engine so it can absorb and dissipate heat. The water pump pumps coolant through the various components in the system and the radiator cools down coolant after it has heated up after passing through the engine. The thermostat controls the flow of coolant based on engine temperature while the cooling fan draws air through the radiator when the car isn't moving fast enough for unforced air to cool things down on its own.

The mechanical advantage (MA) of an inclined plane is the effort distance divided by the resistance distance. In this case, the effort distance is the length of the ramp and the resistance distance is the height of the green box:

MA = \( \frac{d_e}{d_r} \) = \( \frac{24 ft.}{8 ft.} \) = 3

To solve this equation, isolate the variable for which you are solving (b) on one side of the equation and put everything else on the other side.

3b + 2y = 9b - 9y + 8
3b = 9b - 9y + 8 - 2y
3b - 9b = -9y + 8 - 2y
-6b = -11y + 8
b = \( \frac{-11y + 8}{-6} \)
b = \( \frac{-11y}{-6} \) + \( \frac{8}{-6} \)
b = 1\(\frac{5}{6}\)y - 1\(\frac{1}{3}\)

Connecting the 8 batteries in series multiplies their voltage while keeping their current the same yielding a 72V 15A configuration. Connecting the 8 batteries in parallel multiplies their current while keeping their voltage the same yieleding a 9V 120A configuration. Using a series-parallel connection, 4 batteries can be connected in series and 4 can be connected in parallel resulting in a 36V 60A configuration.

The electromagnetic spectrum covers all possible wavelengths and frequencies of radiation.  From lowest frequency (longest wavelength) to highest frequency (shortest wavelength) radiation: radio waves → microwaves → infrared waves → visible light → ultraviolet light → X-rays → gamma rays.

The acids produced by the pancreas contain several enzymes that aid in digestion.  Lipase converts fat to glycerol and fatty acids. Pancreatic amylase breaks down complex carbohydrates into simple sugars. Trypsin converts polypeptides (the building blocks of protein) into amino acids.

To divide fractions, invert the second fraction and then multiply:

\( \frac{4}{6} \) ÷ \( \frac{4}{8} \) = \( \frac{4}{6} \) x \( \frac{8}{4} \)

To multiply fractions, multiply the numerators together and then multiply the denominators together:

\( \frac{4}{6} \) x \( \frac{8}{4} \) = \( \frac{4 x 8}{6 x 4} \) = \( \frac{32}{24} \) = 1\(\frac{1}{3}\)