Examkin

Question

Difficulty: MediumUnit Conversions

An agricultural drone sprays a liquid fertilizer at a constant rate of 120120 milliliters per second. The drone flies at a constant speed, covering 1.51.5 hectares per hour. If the drone operates continuously at this rate, how many liters of fertilizer are sprayed per hectare?

(Note: 11 liter = 1,0001,000 milliliters)

  1. A
    4.8
  2. 288Answer
  3. C
    432
  4. D
    648

Answer

The drone sprays 288 liters of fertilizer per hectare.
To find the number of liters sprayed per hectare, the rate of spraying must be converted from milliliters per second to liters per hour, and then divided by the coverage rate of hectares per hour. First, multiply the spray rate of 120120 milliliters per second by the number of seconds in an hour (3,6003,600 seconds) to find that the drone sprays 432,000432,000 milliliters per hour. Next, convert this volume to liters by dividing by 1,0001,000 milliliters per liter, which gives 432432 liters per hour. Finally, divide this hourly spray volume by the coverage rate of 1.51.5 hectares per hour to obtain 288288 liters per hectare.

Step-by-Step Solution

1
Calculate the volume of fertilizer sprayed in one hour in milliliters.
120 mL/s×3,600 s/h=432,000 mL/h120\text{ mL/s} \times 3,600\text{ s/h} = 432,000\text{ mL/h}
There are 3,6003,600 seconds in one hour, so multiplying the per-second rate by 3,6003,600 gives the volume sprayed per hour.
2
Convert the hourly volume from milliliters to liters.
432,000 mL/h1,000 mL/L=432 L/h\frac{432,000\text{ mL/h}}{1,000\text{ mL/L}} = 432\text{ L/h}
Since 11 liter is equivalent to 1,0001,000 milliliters, divide the volume in milliliters by 1,0001,000 to get the volume in liters.
3
Calculate the volume of fertilizer sprayed per hectare.
432 L/h1.5 hectares/h=288 L/hectare\frac{432\text{ L/h}}{1.5\text{ hectares/h}} = 288\text{ L/hectare}
Divide the total liters sprayed in one hour by the total hectares covered in that same hour to find the rate per hectare.

Key Concept

Unit conversion involving compound rates of volume, time, and area.
Rate this question

Topics

Unit Conversions

More questions from this topic