How does a foam-filled winter coat keep a person warm?

Gam radio signals can usually be heard behind a hill, but fm often cannot. that is, am signals bend more than fm. explain. (radio signals, as we shall see, are carried by electromagnetic waves whose wavelength for am is typically 200 to 600 m and for fm about 3 m.)

Asun-sized star will spend most of its lifetime as a: white dwarf red giant protostar main-sequence star

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)