  In this paper, we prove a logarithmic convexity that reflects an
observability estimate at a single point of time for 1-D heat equation with
dynamic boundary conditions. Consequently, we establish the impulse approximate
controllability for the impulsive heat equation with dynamic boundary
conditions. Moreover, we obtain an explicit upper bound of the cost of impulse
control. At the end, we give a constructive algorithm for computing the
impulsive control of minimal $L^2$-norm. We also present some numerical tests
to validate the theoretical results and show the efficiency of the designed
algorithm.
