If your front lawn is 20.0 feet wide and 20.0 feet long, and each square foot of lawn accumulates 1150 new snowflakes every minute, how much snow, in kilograms, accumulates on your lawn per hour? Assume an average snowflake has a mass of 1.60 mg.

44,160,000 mg/hr

Explanation:

If the lawn is 20 feet wide by 20 feet long this is 400 square feet.

on each of these 400 square feet in one minute are 1150 new snow flakes which makes 460,000 in total.

If each snowflake weighs 1.60 mg then 460,000 is 736,000 mg. But this is only per minute.

60 minutes in an hour is 44,160,000 mg of new snowflakes on that lawn in one hour.