A Pebble Is Dropped in a Lake;and It Produces Ripples

question 36

Multiple Choice

A pebble is dropped in a lake;and it produces ripples with a frequency of 0.50 Hz.When should a second pebble be dropped at the same place to produce destructive interference?

• A)0.50 s after the first
• B)0.75 s after the first
• C)1.0 s after the first
• D)1.5 s after the first
• E)2.0 s after the first

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Definitions:

Circadian

Relating to biological processes that display an endogenous, entrainable oscillation of about 24 hours.

Microsleep

A brief episode of sleep which may last for a second or two to a half-minute, occurring when someone is apparently awake and often goes unnoticed by the person experiencing it.

Threshold

The minimum level of stimulus intensity required for a sensation to be perceived or a response to be elicited.

Sleep Cycles

The progression through various stages of non-REM and REM sleep that repeats cyclically throughout a typical night's rest.