For each object, compare the density of the whole object with the densities of the pieces. What do you notice about the densities?

Which is not a source of noise pollution? a)airplanes b)acid rain c)machines d)cars

In 1980, alfa romeo introduced the first system to smooth a rough idle caused by ignition and camshaft timing changes.

(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.)