The energy possessed by an oscillating pendulum of a clock is _____.

A student carries a bag weighing $5 \mathrm{kg}$ from the ground floor to his class on the first floor that is $2 \mathrm{m}$ high. The work done by the boy is ______.

($\mathrm{g}=10 \mathrm{m}/{\mathrm{s}}^2$)