A particle with charge Q and mass M has instantaneous speed u1 when it is at a position where the electric potential is V1. At a later time, the particle has moved a distance R away to a position where the electric potential is V2. Which of the following equations can be used to find the speed u2 of the particle at the new position?
a. 1/2M(μ2^2-μ1^2)=Q (v1-v2)
b. 1/2M(μ2^2-μ1^2)^2=Q(v1-v2)
c. 1/2Mμ2^2=Qv1
d. 1/2Mμ2^2=1/4πx0 (Q^2/R)