A 3.0 kg flowerpot sits on a balcony 6.5 m above the ground…

Step 1. (a) $U = 3.0\ \text{kg} \times 9.8\ \text{m/s}^2 \times 6.5\ \text{m} = 191.1\ \text{J}$.

Step 2. (b) $h = 6.5\ \text{m} - 0.80\ \text{m} = 5.7\ \text{m}$: $U = 3.0\ \text{kg} \times 9.8\ \text{m/s}^2 \times 5.7\ \text{m} = 167.6\ \text{J}$.

Step 3. (c) The drop is $6.5\ \text{m} - 2.0\ \text{m} = 4.5\ \text{m}$ on either choice: $\Delta U = 3.0\ \text{kg} \times 9.8\ \text{m/s}^2 \times 4.5\ \text{m} = 132.3\ \text{J}$.