OAR Mechanical Reasoning Flashcards

A cam converts rotational motion into which type of motion?

Answer: Reciprocating (back-and-forth) linear motion

A cam's irregular profile converts the rotational input into linear reciprocating motion in the follower.

A 500 N load is lifted using a ramp that is 5 m long and 1 m high. Ignoring friction, what effort force is required to push the load up the ramp?

Answer: 100 N

Mechanical advantage of inclined plane = length/height = 5; Force = 500/5 = 100 N.

Which of the following is the BEST conductor of electricity?

Answer: Copper

Copper has very low electrical resistivity and is the most common electrical conductor used in wiring.

A pitch propeller creates thrust by pushing water backward. If a propeller's pitch is 12 inches, it theoretically advances how far per revolution?

Answer: 12 inches

Propeller pitch is the theoretical distance it advances through the water in one full revolution.

A sound wave travels from air into water. Its speed will:

Answer: Increase because water transmits sound better

Sound travels approximately 4.3 times faster in water than in air due to water's greater bulk modulus.

A wrench slips off a bolt head because the wrench opening is slightly too large. This is most likely to cause:

Answer: The bolt head to round off (strip)

An oversized wrench rocks on the corners of the bolt head, shearing them off and rounding the head.

A flywheel stores energy as rotational kinetic energy. Doubling its rotational speed will change its stored energy by a factor of:

Answer: 4 (quadruples)

Rotational KE = ½Iω²; doubling ω (speed) squares the effect, quadrupling the stored energy.