A Crank Is Being Turned Clockwise at 120 Rev/min

question 33

Multiple Choice

A crank is being turned clockwise at 120 rev/min. The handle is 10 cm from the axle of the crank. An observer some distance away sees the crank edge-on so he only perceives the vertical motion of the crank and not the horizontal motion. What equation describes the motion of the handle seen by the observer if at t=0 the crank is at y = 0 and moving in the negative y direction?

• A)y = (10 cm)cos((12.6 rad/s)t +3π/2)
• B)y = (10 cm)cos((12.6 rad/s + π)t)
• C)y = (10 cm)cos((12.6 rad/s)t - π/2)
• D)y = (10 cm)cos((12.6 rad/s)t)
• E)y = (10 cm)cos((12.6 rad/s)t + π/2)

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Definitions:

Glucose

An elementary sugar critical for energy in living organisms and a key element of many carbohydrate compounds.

Principle Sugar

The primary type of sugar that is prevalent or most important within a particular context, such as glucose in human blood.

Nucleotides

Organic molecules that serve as the monomers, or building blocks, of nucleic acids like DNA and RNA, composed of a nitrogenous base, a sugar, and one or more phosphate groups.

Sugars

Sweet-tasting, soluble carbohydrates, essential for energy source in living organisms, and come in various forms including glucose, fructose, and sucrose, commonly found in fruits, vegetables, and honey.