1. Confirm or disprove Ernest's work by selecting two different points and applying the slope formula. Be sure to identify the points you chose. (2 points) 2. What does the slope tell you about the rate of change in elevation during Ryan's uphill climb? What was the total elevation change? (2 points: 1 for identifying the rate of change, 1 for the total elevation change)
3. What is the slope of the graph between 120 and 150 minutes? What does this mean in terms of change in elevation? (2 points: 1 for the slope, 1 for the explanation)

The rate of decay of a radioactive substance depends upon the amount present initially. the mass y (mg) of the radioactive substance cobalt-60 present in a sample at time t (years) is represented by the exponential equation y=50e −0.1315 t . answer the following questions in complete sentences. 1. how does the exponential equation above compare to the equation for simple interest that is compounded continuously? explain the similarities. 2. what is the initial amount of cobalt-60 in the sample? 2. how much cobalt-60 is left after 8.4 years? show your work. 3. what would be the y-intercept of the graph? what does it represent? 4. after how many years will the amount of cobalt-60 left be 6.25 mg? explain what happens to the cobalt-60 after 50 years? 5. discuss some “real-world” examples and uses of cobalt-60