2. The diagram below shows three positions, A, B, and C, in the swing of a pendulum, released from rest at point A. [Neglect friction.) Which statement is true about this swinging pendulum?

a)The potential energy at B equals the potential energy at C.
b)The speed of the pendulum at A equals the speed of the pendulum at B.
c)The potential energy at A equals the kinetic energy at B.
d)The potential energy at A equals the kinetic energy at C.

(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.)