If an elephant has a net force of 10000 N downward while experiencing an upward force of 9000 N from air resistance, what is the elephant's gravitational force downward? -1000 N, downward
-20000 N, downward
-19000 N, downward
-0 N, the forces are balanced

(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.)