Which statement best describes the term absolute threshold?
a. it refers to the maximum amount of information that a person can process.
b. it refers to the lowest intensity at which a person can detect stimuli.
c. it refers to the minimum change in intensity of stimuli that a person can detect.
d. it refers to the amount of physical energy that a person can convert to electrical energy.

Scientists use laser range-finding to measure the distance to the moon with great accuracy. a brief laser pulse is fired at the moon, then the time interval is measured until the "echo" is seen by a telescope. a laser beam spreads out as it travels because it diffracts through a circular exit as it leaves the laser. in order for the reflected light to be bright enough to detect, the laser spot on the moon must be no more than 1.0 km in diameter. staying within this diameter is accomplished by using a special large-diameter laser. part a if λ = 540nm , what is the minimum diameter of the circular opening from which the laser beam emerges? the earth-moon distance is 384,000 km. express your answer to two significant figures and include the appropriate units.

Why is metal often used for cooking pan?

How to tell if a molecule is polar or nonpolar with electronegativity