1. How long will an investment take to double if it earns interest compounded continuously at an annual rate of 5%?
2. How much will $5000 be worth in 25 years if it earns interest compounded continuously at 8%?

For Questions 3 and 4: A cup of water was heated to a temperature of 90°. It was placed in a refrigerator that had a temperature of 11°C. The water cooled to a temperature of 17°C in 30 minutes.

3. Find the value of k in the differential equation tL' = –k · (tL – tS).
4. Predict the temperature of the water in 60 minutes.

For Questions 5 and 6: A capacitor discharges voltage such that v(0) = 8.9 and v(30) = 1.7.

5. Find the value of k in the differential equation V' = kV
6. Find the half-life of the capacitor.

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