Step 1: Compare with the standard SHM equation.
The given displacement is
\[
x=2\cos(2t).
\]
Comparing with
\[
x=A\cos(\omega t),
\]
we get
\[
A=2\,\text{m}
\]
and
\[
\omega=2\,\text{s}^{-1}.
\]
Step 2: Find the maximum velocity.
For simple harmonic motion,
\[
v_{\max}=A\omega.
\]
Therefore,
\[
v_{\max}=2\times 2
\]
\[
v_{\max}=4\,\text{m s}^{-1}.
\]
Step 3: Calculate the maximum kinetic energy.
The maximum kinetic energy is
\[
K_{\max}=\frac{1}{2}mv_{\max}^2.
\]
Given,
\[
m=2\,\text{kg}.
\]
Hence,
\[
K_{\max}
=
\frac{1}{2}(2)(4)^2
\]
\[
K_{\max}=16\,\text{J}.
\]
Step 4: Final conclusion.
Therefore,
\[
\boxed{16\ \text{J}}
\]