Question

question
which of the contexts below represents exponential decline or decay?
answer
money invested in a savings account grows at an annual rate of 4.1%.
a certain population of 12 aggressive zombies doubles every week.
snow was melting at a rate of 2.5 inches per hour.
a radioactive compound decays at a rate of 5% per hour.

Explanation:

Exponential decay is a process where a quantity decreases by a fixed percentage rate over time.

• Savings account growth is exponential growth, not decay.
• Zombie population doubling is exponential growth.
• Snow melting at a fixed inches per hour is linear decay, not exponential.
• The radioactive compound decreasing by 5% per hour fits exponential decay, as it's a fixed percentage decrease over time.

Answer:

A radioactive compound decays at a rate of 5% per hour.