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A secondary school has a population of 1500 students and 30 standard classrooms. Assuming a 5-day class week with solid waste pickups on Wednesday and Friday before class starts in the morning, determine the size of storage container required. Assuming waste is generated at a rate of 0.11 kg/ plus 3.6 kg per room and that the density of uncompacted waste is 120 kg/m3. Standard container sizes (m3) are as follows: 1.5, 2.3, 3.0 and 4.6.

User Brinsley
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Final answer:

To accommodate the waste generated by the secondary school, a storage container with a capacity of 2.3 cubic meters is required after accounting for the volume reduction by a trash compactor. The density of the rubbish is increased by a factor of approximately 2.857 after compaction.

Step-by-step explanation:

To determine the size of the storage container required for the secondary school's solid waste, we must first calculate the total amount of waste generated in a week. Since pickups are on Wednesday and Friday, we can assume waste needs to be stored for a maximum of three days (Monday to Wednesday) and two days (Wednesday to Friday).

Let's calculate the waste produced per day: each student generates 0.11 kg of waste, and each room generates an additional 3.6 kg. Therefore, daily waste (DW) is (0.11 kg/student × 1500 students) + (3.6 kg/room × 30 rooms).

Daily waste = (0.11 × 1500) + (3.6 × 30) = 165 + 108 = 273 kg/day.

Waste for the longest storage period (three days) is 273 kg/day × 3 days = 819 kg. Since the density of uncompacted waste is 120 kg/m³, the volume for the longest period (V) is 819 kg / 120 kg/m³ = 6.825 m³.

Considering the volume reduction by the trash compactor, thus needs to be divided by 0.350: 6.825 m³ / 0.350 = 1.94875 m³.

Selecting the nearest standard container size that can hold the compacted waste, we choose the 2.3 m³ container.

As for the question about trash compactors, a compactor that reduces the volume of its contents to 0.350 of the original volume increases the density of the rubbish by a factor of the inverse of 0.350, which is approximately 2.857 times. This means the compacted density is now 120 kg/m³ × 2.857 ≈ 342.84 kg/m³.

User Sudha
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