The Equation for the Change of Position of a Train $x=\frac{1}{2} a t^{2}+b t^{3}$

Multiple Choice

The equation for the change of position of a train starting at x = 0 m is given by $x=\frac{1}{2} a t^{2}+b t^{3}$ . The dimensions of b are:

A) T-3
B) LT-3
C) LT-2
D) LT-1
E) L-1T-1