Two unknown materials have a coefficient of kinetic friction of 1.3. Without any further information, which of the following options is most likely to be the
coefficient of static friction?
A. 1.2
B. 1.7
C. O
D. -1.3

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