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Automotive Information

A __________ is a drive axle that extends from a transaxle or differential to one of the drive wheels.

half shaft

A half shaft is a drive axle that extends from a transaxle or differential to one of the drive wheels. There are two half shafts per drive axle, one for each wheel, each doing "half" the job.

Electronics Information

Capacitors connected in series produce __________ capacitance compared to capacitors connected in parallel.

less

Capacitors store electricity and are used in circuits as temporary batteries. Capacitors are charged by DC current (AC current passes through a capacitor) and that stored charge can later be dissipated into the circuit as needed. Capacitors connected in series produce less capacitance than capacitors connected in parallel.

Word Knowledge

The words to the song are elusive, as the singer tends to mumble.

evasive

Hard to grasp.

General Science

All surface water is part of the:

hydrosphere

The biosphere is the global ecological system integrating all living beings and their relationships. This includes their interactions with the lithosphere (the rigid outer part of the earth, consisting of the crust and upper mantle), hydrosphere (all surface water), and atmosphere (the envelope of gases surrounding the planet).

Word Knowledge

Jennifer's outspoken criticism of the meal disoncerted the waiter.

unnerve

To throw into confusion.

Mechanical Comprehension

What is the efficiency of a machine has work input of 100 ft⋅lb and work output of 35 ft⋅lb?

35%

Due to friction, a machine will never be able to utilize 100% of its work input. A certain percentage of that input will be lost in overcoming friction within the machine. Effeciency is a measure of how much of a machine's work input can be turned into useful work output and is calculated by dividing work output by work input and multiplying the result by 100:
\( Efficiency = \frac{Work_{out}}{Work_{in}} \times 100 \) \( = \frac{35 ft⋅lb}{100 ft⋅lb} \times 100 \) \( = 35% \) %

Mechanical Comprehension

If a 25 lbs. weight is placed 3 ft. from the fulcrum at the blue arrow and the green box is 6 ft. from the fulcrum, how much would the green box have to weigh to balance the lever?

12.5 lbs.

To balance this lever the torques on each side of the fulcrum must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:

R_ad_a = R_bd_b

where a represents the left side of the fulcrum and b the right, R is resistance (weight) and d is the distance from the fulcrum.

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

R_a = \( \frac{R_bd_b}{d_a} \) = \( \frac{25 lbs. \times 3 ft.}{6 ft.} \) = \( \frac{75 ft⋅lb}{6 ft.} \) = 12.5 lbs.

Mechanical Comprehension

Two gears are connected and the smaller gear drives the larger gear. The speed of rotation will __________ and the torque will __________.

decrease, increase

Connected gears of different numbers of teeth are used together to change the rotational speed and torque of the input force. If the smaller gear drives the larger gear, the speed of rotation will be reduced and the torque will increase. If the larger gear drives the smaller gear, the speed of rotation will increase and the torque will be reduced.

Automotive Information

Another name for the powertrain control module is the __________ control unit.

engine

The main computer or powertrain control module (PCM) uses pre-programmed software to analyze the input received from sensors and produce output signals to adjust vehicle performance and operation. (Engine control unit (ECU) is another name for the PCM.)

Automotive Information

What function does a two-stroke cycle engine perform on the second stroke?

combustion and exhaust

The two strokes of a two-stroke cycle engine are fuel intake and compression then combustion and exhaust.