1. Determine the Visible Height of Each Pillar:
2. Calculate the Buried Height of Each Pillar:
Since each pillar has a total height of 10 units, subtract the visible height from 10 to find the buried height:
3. Calculate the Total Visible Height:
7 + 5 + 3 + 6 + 9 = 30 units
4. Calculate the Total Buried Height:
3 + 5 + 7 + 4 + 1 = 20 units
5. Determine the Ratio:
The ratio of the total volume above the ground to the total volume below the ground is the same as the ratio of their heights because they have equal cross sections.
This ratio is 30:20, which simplifies to 3:2.
Therefore, the ratio of the total volume of the pillars above and below the ground is 3:2.
Let $ a_0, a_1, ..., a_{23} $ be real numbers such that $$ \left(1 + \frac{2}{5}x \right)^{23} = \sum_{i=0}^{23} a_i x^i $$ for every real number $ x $. Let $ a_r $ be the largest among the numbers $ a_j $ for $ 0 \leq j \leq 23 $. Then the value of $ r $ is ________.
A temperature difference can generate e.m.f. in some materials. Let $ S $ be the e.m.f. produced per unit temperature difference between the ends of a wire, $ \sigma $ the electrical conductivity and $ \kappa $ the thermal conductivity of the material of the wire. Taking $ M, L, T, I $ and $ K $ as dimensions of mass, length, time, current and temperature, respectively, the dimensional formula of the quantity $ Z = \frac{S^2 \sigma}{\kappa} $ is: