contestada

Can you help with these two questions?


1)

Scientists are studying a 500 g. sample of a radioactive element. which has an annual decay rate of 11%. How many grams of the sample would be left after 10 years?


Round the answer to two decimal places.

2)

In 2000, the population of an Ohio town was 140,212. The population is expected to grow at a rate of 2.5% each year.


At this rate, what would be the population in 2040?


Round your answer to the nearest whole number.

Respuesta :

Ashraf82

1) 155.91 grams would be left after 10 years

2) The population would be 376,478 in 2040

Step-by-step explanation:

The form of the exponential function is [tex]y=a(b)^{x}[/tex] , where

  • a is the initial amount (y at x = 0)
  • b is the growth/decay factor
  • b = 1 + r, where r is the rate of growth
  • b = 1 - r, where r is the rate of decay

1)

Scientists are studying a 500 grams sample of a radioactive element, which has an annual decay rate of 11%

∵ The initial amount is 500 grams

∴ a = 500

∵ The annual decay rate is 11%

∴ r = 11% = 11 ÷ 100 = 0.11

∵ b = 1 - r ⇒ decay

∴ b = 1 - 0.11 = 0.89

- We need to find how many grams of the sample would be left

  after 10 years

∴ x = 10

- Substitute all of these values in the form of the exponential function

∵ [tex]y=500(0.89)^{10}[/tex]

∴ y = 155.9085996

- Round it to 2 decimal places

∴ y = 155.91

155.91 grams would be left after 10 years

2)

In 2000, the population of an Ohio town was 140,212. The population is expected to grow at a rate of 2.5% each year

∵ The population of an Ohio town was 140,212

∴ a = 140.212

∵ The population is expected to grow at a rate of 2.5% each year

∴ r = 2.5% = 2.5 ÷ 100 = 0.025

∵ b = 1 + r ⇒ growth

∴ b = 1 + 0.025 = 1.025

- We need to find the population in 2040

∵ The number of years is 2040 - 2000 = 40 years

∴ x = 40

- Substitute all of these values in the form of the exponential function

∵ [tex]y=140212(1.025)^{40}[/tex]

∴ y = 376478.1709

- Round it to the nearest whole number

∴ y = 376,478

The population would be 376,478 in 2040

Learn more:

You can learn more about the functions in brainly.com/question/11921476

#LearnwithBrainly

Otras preguntas