Correct Transposition

Is this transposition correct.

Find K from Vp(t) = 5e^-k(100pi.t)^2

Divide both sides by 5

Vp(t)/5 = e^-k(100pi.t)^2

Natural log of both sides

ln(Vp(t)/5) = -k (100pi.t)^2

Divide both sides by (100pi.t)^2

ln(Vp(t)/5) / 100pi.t = -k

Then with my values for Vp(t) and t I can find what K is.

Have I transposed correctly, it seems right to me!

Nearly.
Your last line should be
ln(Vp(t)/5) / (100pi.t)^2 = -k
so
k= -ln(Vp(t)/5) /(100pi.t)^2