Which statement is true about vectors? a. All quantities in physics are not vectors.
b. A vector may have either magnitude or direction.
c. The vector’s length should be proportional to its magnitude.
d. Two vectors can be added only if they have the same direction.

Ascientist notices that an oil slick floating on water when viewed from above has many different colors reflecting off the surface, making it look rainbow-like (an effect known as iridescence). she aims a spectrometer at a particular spot and measures the wavelength to be 750 nm (in air). the index of refraction of water is 1.3