The primary purpose of polarized sunglasses
a.
to block ultraviolet rays.
b.
to block infrared rays.
c.
to block glare from reflections (for example off lakes or roads).
d.
to look cool.

If a clock aboard a space ship traveling at 0.900 c of the speed of light relative to earth chimes once at the beginning of the hour and again when it reads one hour later, how much time would an observer on earth say elapsed between the two chimes?

The mass of a muon is 207 times the electron mass; the average lifetime of muons at rest is 2.21 μs. in a certain experiment, muons moving through a laboratory are measured to have an average lifetime of 7.04 μs. for the moving muons, what are (a) β (b) k, and (c) p? the rest energy of the electron is 0.511 mev.

Ascrew incorporates which other simple machine? lever wheel and axle inclined plane pulley