The radiation our eyes are most sensitive to is the color
A) black at 227 nm.
B) blue at 4,321 nm.
C) violet at 7,000 Angstroms.
D) yellow-green at about 550 nm.
E) red at 6563 Angstroms.
Question 2
According to the inverse square law of light, how will the apparent brightness of an object change if its distance to us triples?
A) Its apparent brightness will decrease by a factor of 3.
B) Its apparent brightness will increase by a factor of 9.
C) Its apparent brightness will increase by a factor of 3.
D) Its apparent brightness will decrease by a factor of 9.