If your front lawn is 17.0 feet wide and 20.0 feet long, and each square foot of lawn accumulates 1150 new snow flakes every minute, how much snow (in kilograms) accumulates on your lawn per hour? assume an average snow flake has a mass of 1.50 mg.

First, we solve the area of the front lawn by multiplying the width with the length.
                          A = l x w = (20 ft) x (17 ft)
                                   A = 340 ft²
Each foot square will accumulate 1150 per minute. Please follow through the conversion that I am about to perform below.
 (340 ft²) x (1150 new snow/ 1ft².min) x (60 min/1 hour) x (1.50 mg/1 new snow) x (1 g/1000 mg) x (1 kg/ 1 g) = 35.19 kilogram of new snow

D)can be increased in a closed system