Which statement is true about the part of the electromagnetic spectrum that is divided into seven ranges of wavelengths?

a. it is one of three parts visible to the human eye.
b. it is the only part visible to the human eye.
c. it is one of two parts visible to the human eye.
d. it cannot be seen by the human eye unless it rains.

Which law represents the thermodynamic statement of the conservation of energy of a system? a. the fourth law b. the first law c. the second law d. the third law

You are given a vector a = 125i and an unknown vector b that is perpendicular to a. the cross-product of these two vectors is a × b = 98k. what is the y-component of vector b?

Which of the following is a direct benefit of the use of assembly lines in production a. laws against theft fraud and coercion are needed to protect free choice. b. the government needs to plan efficient outcomes. c. competition among producers by itself cannot ensure a wide range of consumer choices. d. works pressure the government to guarantee minimum wages