Answer:
36 kg/h
Explanation:
We start calculating the total amount of square feet of the lawn with the rectangle area equation:
Area(rectangle)= long x wide = 20 ft x 16 ft = 320 [tex]ft^{2}[/tex]
Now, for every one of those 320 [tex]ft^{2}[/tex] 1250 new snowflakes accumulates each minute, this means that means that in one minute we get:
# Snowflakes (min) = [tex]320 ft^{2} *1250\frac{flakes}{ft^{2}} =400,000 snowflakes[/tex]
In a minute we have 400,000 snowflakes, then we need to multiply that by the number of minutes in an hour (60 min in an hour):
# Snowflakes (hour) = [tex]400,000\frac{snowflakes}{min}*60 \frac{min}{h}=24,000,000 \frac{snowflakes}{h}[/tex]
If each snowflake has a mass of 1.50 mg (the average), then:
[tex]mass = 24,000,000 snowflakes*1.50\frac{mg}{snowflakes}=36,000,000mg[/tex]
In each kilogram there are 1000000 mg so making this transformation:
36,000,000mg to kg ⇒ [tex]\frac{36,000,000}{1000000}kg=36 kg[/tex]