# A certain material decays at a rate of 1.9% per year. The sample is 260 grams. How much will be left in 11 years?

104,421 results

### Exponential and Logarithmic functions

A certain material decays at a rate of 1.9% per year. The sample is 260 grams. How much will be left in 11 years? How long will it take to have only a 100g sample left?

### algebra

Suppose a sample of Cesium-137 with initial mass of 200 grams decays to a mass of 160 grams voer the course of 10 years. Find the half-life of Cesium-137 (Round to the nearest year) How much Cesium-137 is left in the sample after 60 years? Round to the nearest tenth of a gram.

### Calculus

A certain radioactive material decays exponetially. The percent, P, of the material left after t years is given by P(t)= 100(1.2)^-t a)Determine the half life of the substance

### calculus

The rate at which an amount of a radioactive substance decays is modeled by the differential equation dA/dt = kA, where A is the mass in grams, t is the time in years, and k is a constant. Answer the following. a) If a 100-gram sample of the radioactive substance decays to 95 ...

### Chemistry

It took 109.8 years for a 300.0 mg sample of an unknown radioactive material to completely disintegrate. Calculate the mass of the element (in grams/mole) assuming that the disintegrations per second are constant over the life-time of the sample, and the sample is labeled 100....

### math

Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t)=(.98)^t (b) Estimate the half-life of strontium. (c) If presently...

### College Algebra

The half-life of a radioactive material is about 34.6 years. How much of a 1-gram sample of the material is left after 30 years?

### AP Calculus

An Initial amount of 100 grams of Thorium-234 decays according to the model: dP/dt=-0.02828P (where t is measured in years). a) Find the equation for the amount of Thorium left after t years. b) Determine the half-life of this radioactive isotope c) How long will it take for ...

### College algebra

Sample of 500gms radioactive substance decays according to the function A(t)-500-0.044t where t is the time in years. How much of the substance will be left in the sample after 20 years?round to the nearest whole gram

### Physics

A gram of living plant material with Carbon-14 , decays at a rate of about 16 disintegrations per minute. When the plant dies, the Carbon-14 decays, with a half-life of 5600 years. A gram of the dead plant is found to decay at about 1 disintegration per minute. Calculate the ...

### Pre Calculus

If a 25 mg sample of radioactive material decays to 18.4 mg in 5 years, how long will it take the sample to decay to 20.5 mg?

### Math

A radioactive material has a half life of 500 years. A) Given 20 grams of this material, how much will remain after 1,000 years? B) Given 100 grams of this material, how much will remain after 750 years? Thank you to whom ever can help me :)

### algebra

A radioactive substance decays according to the formula A=A0e^kt where A0 is the initial amount of substance (in grams) A is the amount of substance(in grams) after t years k is a constant The half-life of the substance is 10 years.If we begin with 20g of the substance,how ...

### algebra 2

In the formula A(t) = A0ekt, A is the amount of radioactive material remaining from an initial amount A0 at a given time t, and k is a negative constant determined by the nature of the material. An artifact is discovered at a certain site. If it has 72% of the carbon-14 it ...

### Physics/Math

A 25.0 gram piece of charcoal is found in some ruins of an ancient city. The sample shows a 14C activity, R, of 250 decays/min. How long (in years) has the tree this charcoal came from been dead? I think I have the use the equation: R=lamda*No*e^(-lamda*t) but I am not sure ...

### Math

Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t) = (b) Estimate the half-life of strontium. Answer: Hint: Use your...

### calculus

Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t) = (b) Estimate the half-life of strontium. Answer: Hint: Use your...

### NEED HELP WITH CALC

Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t) = (b) Estimate the half-life of strontium. Answer: Hint: Use your...

### Physics

If a sample of a radioactive isotope has a half-life of 5 year(s), how much of the original sample will be left at the end of the second year? How much will be left at the end of the third year of thr original sample? How much will be left at the end of the fourth year of the ...

### Finance

Omega Instruments has budgeted $300,000 per year to pay for certain ce- ramic parts over the next 5 years. If the company expects the cost of the parts to increase uniformly according to an arith- metic gradient of $1 0,000 per year, what is it expecting the cost to be in year...

### Math

Suppose you wnat to purchase a house for 650,000. Hoe much of the loan would be left after 10 years if the interest rate was 3.8 % and it was a thirty year mortgage? And if you made the montly payments for ten years, and then increase your payment to 4000 per year, how many ...

### Algebra please check my answers

1) The linear function f(x) contains the points (-10, -29) and (-2, 83). If g(x) = 25x - 50, which statement is true? A. The functions f(x) and g(x) both have positive slopes. <<< B. The functions f(x) and g(x) both have negative slopes. C. The function f(x) has a ...

### science

As redioactive material decays and the percentage of new material in the original sample increases, does the age of the sample substance increase, decrease, or remain the same?

### Pre Calculus

Tritium, a radioactive isotope of hydrogen, has a half-life of 12.4 years. Of an initial sample of 69 grams, how much will remain after 75 years? a. 1.5848 grams b. 61.5289 grams c. 0.0000 grams d. 1.0426 grams e. 17.2500 grams

### Physics

The activity of a sample of 35(upper#) 16(lower#)Sulfer (T 1/2= 7.55x10^6 s) is 2.51x10^5 decays per second. WHat is the mass of the sample? m= in grams PLease help me out...Thank you! :)

### Physics!

The activity of a sample of 35(upper#) 16(lower#)Sulfer (T 1/2= 7.55x10^6 s) is 2.51x10^5 decays per second. WHat is the mass of the sample? m= in grams PLease help me out...Thank you! :)

### Physics Plz help me

The activity of a sample of 35(upper#) 16(lower#)Sulfer (T 1/2= 7.55x10^6 s) is 2.51x10^5 decays per second. WHat is the mass of the sample? m= in grams PLease help me out...Thank you! :)

### Physics Plz help me

The activity of a sample of 35(upper#) 16(lower#)Sulfer (T 1/2= 7.55x10^6 s) is 2.51x10^5 decays per second. WHat is the mass of the sample? m= in grams PLease help me out...Thank you! :)

### finance

The Blinkelman Corporation has just announced that it plans to introduce a new solar panel that will greatly reduce the cost of solar energy. As a result, analys now expect the company’s earnings, currently (year 0) $1 per share to grow by 50 percent per year for the next ...

### finance

The Blinkelman Corporation has just announced that it plans to introduce a new solar panel that will greatly reduce the cost of solar energy. As a result, analys now expect the companyâ€™s earnings, currently (year 0) $1 per share to grow by 50 percent per year for the ...

### business

As part of your financial planning, you wish to purchase a new cat exactly 5 years from today. The car you wish to purchase coasts $14,000, and your research indicates that its price will increase by 2% to 4% per year over the next 5 years. a. Estimate the price of the cars at...

### Retirement

1. I would like to retire in 42 years at the age of 65. The average retirement age for women is between 60-62 years of age, and 62-64 for men. 2. My annual amount of money I'll need after retiring would be approxiamately $26,500 (2,205*12=$26,460) using my cost today. Expense ...

### math

Brenda Luai earns $14,260 per year. She is paid 24 times per year and claims 1 exemption. If $19.63 in taxes is withheld from each paycheck, at what rate is she taxed?

### fin

The following tabulation gives earnings per share figures for the Foust Company during the preceding 10 years. The firm’s common stock, 7.8 million shares outstanding, is now (1/1/03) selling for $65 per share, and the expected dividend at the end of the current year (2003) ...

### math check

Brenda Luai earns $14,260 per year. She is paid 24 times per year and claims 1 exemption. If $19.63 in taxes is withheld from each paycheck, at what rate is she taxed?

### Algebra

Jane agrees to buy a car for a down payment of $4000 and payments of $260 per month for 9 years. If the interest rate is 9% per year, compounded monthly, what is the actual purchase price of her car? (Round your answer to the nearest cent.)

### precalc

I am really struggling with a bunch of problems. Any help with any of the following would be greatly appreciated. Thanks 1. ln e^(ln x) - ln(x - 3) = ln 8 2.3e^(6x - 2) = 18 The word problems, especially, are killing me. 3. In the formula A = Iekt, A is the amount of ...

### Economics

Jim signed a new deal for $10 million with the Toronto maple leafs. THe terms of the contract were 1 million immediately and 800,000 per year for the next 5 years (first payment after 1 year) and $1 million per year for the next 5 years (first payment at year 6). If jim's ...

### math algebra

The amount A, of 70 grams of a certain radioactive material remaining after t years can be found by the equation A=70(0.62)^t. When will 10 grams remain?

### Finance

Assume that you are 23 years old and that you place $3,000 year-end deposits each year into a stock index fund that earns an average of 9% per year for the next 17 years. 1. How much money will be in the account at the end of 17 years? 2. How much in account 15 years later at ...

### Finance

EMAR expects to receive $2,000 per year for 10 years and $3,500 per year for the next 10 years. What is the present value of this 20-year cash flow? Use an 7% discount rate.

### math

College is expected to cost $150,000 per year in 18 years, how much should you begin depositing annually at the end of each year to accumulate enough funds to pay the first years tuition at the beginning of the 19th year? earning 6% annual rate of return of the investment

### Finance

Ambrin Corp. expects to receive $2,000 per year for 10 years and $3,500 per year for the next 10 years. What is the present value of this 20 year cash flow. Use a 11% discount rate.

### Maths

ABC corp. expects to receive $2000 per year for years and $3500 per year for the next 10 years. what is the percentage value of this 20 years cash flow? use an 7% discount rate

### Finance

ABC corp. expects to receive $2000 per year for years and $3500 per year for the next 10 years. what is the percentage value of this 20 years cash flow? use an 7% discount rate

### Math

How do I solve this if there is no equation to this 1. The population of the bacteria in a Petri dish increases by a factor of 10 every 10 hour. If there are initally 20 bacteria in the dish, how long will it take before the population increases to 60,000 to the nearest tenth ...

### MATH

The value V of a machine t years after it is purchased is inversely proportional to the square root of t+2. The initial value of the machine is $10,000. Find the rate of depreciation when t=5 . Round your answer to two decimal places. A. -381.80 PER YEAR B. -1889.82 PER YEAR C...

### Finance

Your client is 40 years old and she wants to begin saving for retirement, with the first payment to come one year from now. She can save 5000 per year; and you advise her to invest it in the stock market, Which you expect to provide and average 9% in the future. A) If she ...

### Physical Science

A gram of radioactive material has a half-life of one year. After four years how much radioactive material will be left...0g, 1/2g, or 1/4g? None of the above. The answer one-half to the fourth power.

### finance

Suppose that you are 25 years old and you have two options to save money for retirement. Plan A allows you to save $3000 per year for the next 20 years, then sit for 20 years and finally draw on it for the following 30 years. Plan B allows you to wait 20 years and save $20,000...

### chemistry

Calculate the residence time of sodium in millions of years if the total amount of sodium in the oceans is 1.5 x 10 to the 22 grams, and is supplied to the ocean at a rate of 2.2 x 10 to the 14 grams per year.

### finance

Starting a year from now and making 10 yearly payments, Pierre would like to put into a retirement account enough money so that, starting 11 years from now, he can withdraw $30000 per year until he dies. Pierre is confident that he can earn 8% per year on his money for the ...

### Math - Exponential Decay

Radium decays exponentially. Its half-life is 1,690 years. How long will it take for a 50-gram sample of radium to be reduced to 5 grams? 1/2P = Pe^(-1690k) (ln1/2)/(-1690) = k 4 x 10^-4 = k 5 = 50e^-kt ln0.1 = -kt ln0.1/-k = t 5,630 years = t ...but textbook answer is 5,614 ...

### BUSINESS FINANCE

John Smith wants $80,000 per year in his retirement. He plans to be in retirement for 30 years. He has 25 years to work. Assume an interest rate of 7% for the next 55 years. How much does he need to deposit at the end each year while he is working in order to have saved enough...

### math

Brenda earns $14,260 per year. paid 24 times a year with 1 exemption. If $19.63 in taxes is withheld from each check at what rate is she taxed

### science

A substance has a half-life of 10,000 years and an initial mass of 1,000 grams. How many years will pass before only 250 grams of the substance's parent material is left?

### economics

Tom plans to gamble each year for the next 20 years, starting at at the end of year 1. If he loses 4.47 dollars in odd years (i.e., years 1, 3, 5, etc) and wins 7.46 dollars in even years (i.e., years 2,4, 6 etc), what will be Tom's (internal) rate of return per year from ...

### Science

If 15% of the radioactive material decays in 5 days, what would be the percentage of amount of original material left after 25 days?

### Calculus-derivatives

Verify if these are correct answers. 1. The derivative of f(x)=e^2x -e^-2x is f'(x)=2e^2x - 2e^-2x? 2.A certain radioactive substance is decaying so that at time t, measured in years, the amount of the substance, in grams, given by the function f(x)=3e^-3t. What is the rate of...

### Finance

If $12,000 is invested in a certain business at the start of the year, the investor will receive $3,600 at the end of the next four years. What is the present value of this business opportunity if the interest rate is 7% per year?

### Pre Calculus 1

thirty percent of a radioactive substance decays in four years. assuming the decay is exponential, find the half life of the substance. the beginning of 1975 the population of a country was 40 million and growing at a rate of 3% per year. Assume that the growth is exponential...

### Algebra-Problems

Please help with my word problems? Solve the problem. The rabbit population in a forest area grows at the rate of 6% monthly. If there are 260 rabbits in April, find how many rabbits (rounded to the nearest whole number) should be expected by next April. Use y=260(2.7)^0.06t...

### Environmental Science 11th grade

If half of a quantity of radioactive material decays in 10 years, in another 10 years?

### math

A certain sum is deposited in a bank which gives compound intrest at certain rate. The intrest on the amount is rs.440. In the first 2 years and rs.728 in the first 3 years what is the rate of interest per annum.

### Math

Suppose that a certain material has a half life of 25 years, and there are A(t)=10(1/2)^t/25 grams remaining after t years. find: i) initial amount i) Amount after 80 years Solutions i) A(0)=10(1/2)^(0/25) =10(1/2)^0 =10(1) =10 ii)A(80)=10(1/2)^(80/25) =10(1/2)^(16/5) =10(0....

### Word Problems-Math

Please help with my word problems? Solve the problem. The rabbit population in a forest area grows at the rate of 6% monthly. If there are 260 rabbits in April, find how many rabbits (rounded to the nearest whole number) should be expected by next April. Use y=260(2.7)^0.06t...

### Fin- Management

David purchased a $100,000 participating whole life policy. The annual premium is $2,280. Projected dividends for the first 20 years are $15,624. The cash value after 20 years will be $35,260. If the premiums were invested at 5 percent for 20 years, the premiums would grow to...

### BUSINESS MATH

: The Crescent Corporation just paid a dividend of $2 per share and is expected to continue paying the same amount each year for the next 4 years. If you have a required rate of return of 13%, plan to hold the stock for 4 years, and are confident that it will sell for $30 at ...

### Stat 1

Seventy million pounds of trout are grown in the U.S. every year. Farm-raised trout contain an average of grams of fat per pound, with a standard deviation of grams of fat per pound. A random sample of farm-raised trout is selected. The mean fat content for the sample is grams...

### statistics

Seventy million pounds of trout are grown in the U.S. every year. Farm-raised trout contain an average of 32 grams of fat per pound, with a standard deviation of 7.5 grams of fat per pound. A random sample of 34 farm-raised trout is selected. The mean fat content for the ...

### statistics

Seventy million pounds of trout are grown in the U.S. every year. Farm-raised trout contain an average of 32 grams of fat per pound, with a standard deviation of 7.5 grams of fat per pound. A random sample of 34 farm-raised trout is selected. The mean fat content for the ...

### FINANCE 200

You receive $5000 three years from now. The discount rate is 8 percent. What is the value of your investment two years from now? (Multiply 5000 by .926 (one year discount rate at 8%) Will it be worth $9,260?

### Finance

Given an interest rate of 6.25% compounded annually, how much would you accumulate if you started with $3,250 and then contributed $1,950 per year (at the end of each year) for 13 years?

### Pre-Calculus

It is well known that superman can withstand as much as 3 grams of Green Kryptonite indefinitely. However, exposure to more than 3 grams for more than 13 hours is fatal. Assume that Kryptonite decays at an hourly rate of 5.35% If superman is trapped in a room with 6 grams of ...

### BUSINESS MATH

Part B: The Crescent Corporation just paid a dividend of $2 per share and is expected to continue paying the same amount each year for the next 4 years. If you have a required rate of return of 13%, plan to hold the stock for 4 years, and are confident that it will sell for $...

### Finance

You plan to start an elite 2 year MBA program on September 1, 2015. Tuition is $75,000 per year payable on that date, at the beginning of the school year. You expect tuition to increase by 6% in the second year. If the market interest rate is 3% per year, how much would you ...

### calculating annuity

IF a company will generate 80,000 in annual revenue each year for the next eight years and the interest rate is 8.2% what is the present value of the savings? An EXCEL spreadsheet will be helpful for these types of calculations. Let S1 be savings in year 1, S2 in year 2, and ...

### Algebra 1 honors

Mr. Oliver invested a total of $6400, part at 9% per year and the remainder at 8% per year. At the end of 2 years and 6 months, he had earced a total investment of $1380 in simple interest. How much ded he invest at each rate. I have to come up with the equation.

### Pre-Cal

The population of Las Vegas, Nevada in 2000 was 478,000 and is increasing at the rate of 6.28% per year. At this rate, when will the population reach 1 million people? a)1.51 years b)2.32 years c)12.12 years d)10.84 years

### pre calc

A 50 gram sample of radioactive strontium will decay to 32 grams in 18 years. a. Find an equation that will model how much of our sample M will remain after t years.

### Corporate finace

suppose your firm is planning to invest in a project that will generate the following income stream:a negative flow $250000 per year for 5 years, a positive floww of $550000 in year 6, and a positive flow of $600000 per year in the year 7 through9. What is the present value of...

### math

Jeanette wishes to retire in 30 years at age 55 with retirement savings that have the purchasing power of $300,000 in today’s dollars. 1. If the rate of inflation for the next 30 years is 2% per year, how much must she accumulate in her RRSP? 2. If she contributes $3000 at ...

### Finance

The Seneca Maintenance Company currently (that is, as of year 0) pays a common stock dividend of $1.50 per share. Dividends are expected to grow at a rate of 11 percent per year for the next 4 years and then to continue growing thereafter at a rate of 5 percent per year. What ...

### math

Inflation is running 2% per year when you deposit $1000 in an account earning interest of 13% per year compounded annually. In constant dollars, how much money will you have two years from now? (Hint: First calculate the value of your account in two years' time, and then find ...

### chemistry

a 15g sample of gold-198 decays in 3g in 6 days. how much will be left after 8 days?

### math check

1.)Jenna earns $16,250 per year. She pays 6% of her earnings to her pension fund. Her health insurance costs $81.50 per month and she has $55 taken from her monthly paycheck for savings. What are her total deductions for the year? =a.)$2,613 b.)$1,625 c.)$815.50 2.)Maribel's ...

### Finance

Th e Seneca Maintenance Company currently (that is, as of year 0) pays a common stock dividend of $1.50 per share. Dividends are expected to grow at a rate of 11 percent per year for the next four years and then to continue growing thereaft er at a rate of 5 percent per year. ...

### Pre Calculus

17. population growing at an annual rate r will triple in a time t given by the formula t = ln 3/r If the growth rate remains constant and equals 9% per year, how long will it take the population of the town to triple? a. 6 . 6 years b. 1 years c. 5 . 3 years d. 2 . 2 years e...

### fin 200 question

Jean will receive $8,500 per year for the next 15 years from her trust. If a 7% interest rate is applied, what is the current value of the future payments? Describe how you solved this problem, including which table (for example, present value and future value) was used and ...

### Finance

We are considering the introduction of a new product. Currently we are in the 34% tax bracket with a 15% discount rate. This project is expected to last five years and then, because this is somewhat of a fad project, it will be terminated. The following information describes ...

### Math Analysis

31. Radioactive decay of material is determined using the formula N = Noe^-kt. Find the constant k for Plutonium-239 given that its half-life is 24,390 years. ==> I don't really get where to start here because the problem does not give you how much Plutonium-239 there is. I...

### Maths

Can you help me with this? I don't know how to figure it out. the population growing at an annual rate r will triple in a time t given by the formula t = ln 3/r If the growth rate remains constant and equals 9% per year, how long will it take the population of the town to ...

### Personal Finance

Assume that you are 23 years old and that you place $3,000 year-end deposits each year into a stock index fund that earns an average of 9.5% per year for the next 17 years. how much money will be in the account at the end of 17 years.

### Algebra I

A sample of radioactive material weighing 45 grams has a decay rate of 4.25% each day. The equation y = 45(2.7)–0.0425t can be used to find the amount of material that still remains, where t is the number of days that have passed. Approximately what is the amount of material...

### chemistry

A 1.00-g sample of carbon from a modern source gave 15.3 disintegrations per minute. A sample of carbon from an “old” source gave 920 disintegrations per hour. What is the age of the “old” sample of carbon? The half-life of carbon-14 is 5.73×103 year. a. about 34,400 ...

### chemistry

A 1.00-g sample of carbon from a modern source gave 15.3 disintegrations per minute. A sample of carbon from an “old” source gave 920 disintegrations per hour. What is the age of the “old” sample of carbon? The half-life of carbon-14 is 5.73×103 year. a. about 34,400 ...

### Chemistry H

60.0 grams of Th-210 with a half life of 50,000 years is allowed to decay for 250,000 years. How much of the original quantity remains? In addition, Th-210 decays via beta emission. Write the equation for its transmutation.

### business finance

Your client is 40 years old, and she wants to begin saving for retirement, with the first payment to come one year from now. She can save RM5,000 per year, and you advise her to invest it in the stock market, which you expect to provide an average return of 9 percent in the ...

### math..urgent pleasehelp :(

the purchasing power (in dollars) of an annual amount of A dollars after t years of 5% inflation decays according to P= Ae^-0.05t a) how long will it be before a pension of $60,000 per year has a purchasing power of $30,000 b) how much pension A would be needed so that the ...