The Figure Shows Two Point Sources of Light, a and B

question 19

Multiple Choice

The figure shows two point sources of light, A and B, that emit light waves in phase with each other. A is distant 3λ from point P. B is distant 5λ from P. (λ is the wavelength.) The phase difference between the waves arriving at P from A and B is

• A) 0 rad.
• B) π rad.
• C) 2π rad.
• D) 3π rad.
• E) 4π rad.

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Definitions:

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A statistical measure that allows comparison of mortality rates among different populations by removing the effects of age differences.

Attributable Risk

The difference in the rate of a condition between an exposed population and an unexposed population, which can be attributed to the exposure.

Cohort Study

An observational study design that follows a group of people over time to investigate the causes of disease and establish links between risk factors and health outcomes.

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A medical condition commonly known as a heart attack, which occurs when blood flow to the heart is blocked, causing heart muscle damage.