Question

A log of wood of dimension 2 metre ?20 centimetre?10centi metre is cut into small blocks of 10 cm?5 cm?4 cm. How many blocks will we get? What will be the total surface area of all these blocks?

Answer 1

Hi,
$$\begin{gathered} \mathrm{The}\mathrm{number}\mathrm{of}\mathrm{block} \\ =\frac{\mathrm{volume}\mathrm{of}\mathrm{bigger}\log }{\mathrm{volume}\mathrm{of}\mathrm{smaller}\mathrm{block}} \\ =\frac{200\times 20\times 10}{10\times 5\times 4}=200 \\ \mathrm{Now}\mathrm{total}\mathrm{surface}\mathrm{area}\mathrm{of}\mathrm{these}\mathrm{smaller} \\ =200\times \mathrm{TSA}\mathrm{of}\mathrm{one}\mathrm{smaller}\mathrm{block} \\ =200\times \left[2\left(\mathrm{lb}+\mathrm{bh}+\mathrm{hl}\right)\right] \\ =400\left(50+20+40\right) \\ =44,000{\mathrm{cm}}^2 \end{gathered}$$
Regards