Apiece of tape is pulled from a spool and lowered toward a 190-mg scrap of paper. only when the tape comes within 8.0 mm is the electric force magnitude great enough to overcome the gravitational force exerted by earth on the scrap and lift it.

(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.)