Determine when an object is accelarating

(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.)

If the new moon happens on january 15th, what shape will it be on february 6th?

By what factor does the drag force on a car increase as it goes from 65 to 110 km/h?