School bags are provided with wider straps to reduce pressure on the shoulders of children. 

The weight of air in a column of the height of the atmosphere and area $15 \mathrm{cm}\times 15 \mathrm{cm}$ is nearly equal to the weight of an object of mass:
(Take acceleration due to gravity equal to $10 {\mathrm{ms}}^{-2}$ and the atmospheric pressure equal to $101325 \mathrm{Pa}$).