First, calculate the distance moved using the formula for average velocity:

\(s = \frac{(u + v)}{2} \times t\)

where \(u = 0\) m/s (initial speed), \(v = 0.5\) m/s (final speed), and \(t = 7\) s.

\(s = \frac{(0 + 0.5)}{2} \times 7 = 1.75\) m

Next, calculate the potential energy gain:

\(\text{PE gain} = mgh = 160 \times 9.8 \times 1.75 = 2800\) J

Calculate the kinetic energy gain:

\(\text{KE gain} = \frac{1}{2} mv^2 = \frac{1}{2} \times 160 \times (0.5)^2 = 20\) J

The total work done (WD) by the crane is the sum of the potential energy gain and the kinetic energy gain:

\(\text{WD} = 2800 + 20 = 2820\) J