Y1

As shown, I have the answers, just need the work shown please and thank you!!(:

1. Estimate how many times an average human heart beats over the course of the lifetime of its "owner." Very few things humans can make with moving parts that are that durable! What are your assumptions (your answer may be different because of that, but not by much)? answer: 2.5x10^9 beats

2. The freshwater ice in the Greenland ice sheet constitutes about 1/9 of the world's freshwater ice. What percentage of the world's freshwater ice is this? answer: 11%

3. Approximately 9% of US energy comes from nuclear power plants. The output of those plants is electricity, and this nuclear-generated electricity represents 20% of US electrical energy. Use these facts to determine the fraction of the total US energy supply that is in the form of electricity.

4. A story published by NYT on July 9, 2018 stated that a major algae bloom formed in Lake Okeechobee and connected waterways in Florida during that summer. The principal causes were a combination of warm temperatures and heavy runoff of nitrogen and phosphorus from fertilizer used on adjoining land. The article states that the lake has a surface area of 730 square miles. According to areal photographs, on June 12, only 1% of the lake was covered, but the area of the bloom reached 90% by July 8. How fast on average did the bloom grow, measured in percent per day? In square miles per day?

answer: 3.4%/day, 25mi^2/day